A 2019 Winter Course In OLLI At VPC - UC
A 2019 Winter Course in OLLI at VPCRichard Wendel MD, MBA, Graduate GemologistModerator
Some Goals and Objectives of the Course1) Share my experiences with the Gem Business2) Engender a greater appreciation for a range of gem stonesand fine jewelry3) Understand some of the basic physical and chemicalproperties of diamonds and colored stones4) Discuss the instruments used in gem identification,evaluation and authentication5) Sharpen your skills in buying and selling jewelry6) ‘Show and Tell’ venue to discuss your experiences, andview your precious jewelry treasures7) Perspectives from two local independent Jewelry Storeowners who will add to the discussion of jewelry design,repair, appraisals and antique jewelry.
CullinanDiamond isthe largestgem-qualityroughdiamond everfound,weighing3,106.75carats
Birth Stones according to the AmericanNational Retail Jewelers Association 1912
Zodiac, Guardian Angel, Apostolic andSynthetic etc. lists of birthstones. Take you pick and any gift is appreciated!
General Ground Rules to Consider when purchasingjewelry Typical markups in jewelry stores are 200-300 percent Perfecting the art of Haggling (not just for trips to theCaribbean, Mexico or Turkey) Ways to analyze a jewelry piece to minimize impulse buying Many jewelry store ‘clerks’ know little about theirmerchandise and provide incorrect information The pitfalls of overseas purchases The New York market and 47th street Trunk shows, discount days and special offers General guidelines for Investing in precious metals and gems Protecting and insuring your valuables Buy to enjoy your jewelry purchases
The Four evaluation criteria for Diamonds; thesecriteria are also used with other gem stones aswell, but with less precision. Only Diamonds andPrecious metals fall into fairly standardizedcriteria making them a commodity. 1. Carat 2. Cut 3. Clarity 4. Color
There are 100 points in a 1 carat stonewhich weights 200 mg; a 5 carat stoneweights just 1 gram.
Cut
Ideal Proportions of a round brilliant diamond and terminology:proportions have been perfected mathematically based on RI
Standard Cutting Styles The modern round brilliant consists of 58facets or 57 if the culet is excluded; 33 on thecrown (the top half above the middle or girdle ofthe stone) and 25 on the pavilion (the lower halfbelow the girdle). Older diamond jewelry often had fewer facetslike the old miner and European cuts in olderpieces. Step cut diamonds like an emerald or pear shapecut usually have the same number of facets asthe round brilliant cut.
Other Popular Cuts that are less expensive becausethey save a greater percentage of the rough material Princess Cut diamond which is a square cutdiamond with sharp corners and generally 58facets Radiant Cut is similar but more rectangularwith trimmed corners.
Color of ‘Colorless’ DiamondsD-Z (entire alphabet starting with Dthen E,F,G,H,I,J,K,L,M-----Z which is aCanary Diamond)Color grading measures the amount of yellow inthe stone and is as important as the other threeCs in street value. This is where the dealer canand often does deceive the retail jeweler andretail customer.
Need a master stone set or known standard stones withmorning eyes to accurately grade color (north light)1. DIAMONDS GRADED D,E AND F ARE COLORLESS2. DIAMONDS G,H,I,J ‘FACE-UP’ COLORLESS3. DIAMONDS K,L,M,N AND BELOW SHOWINCREASING YELLOW FACE-UP (VISIBLE TO THENAKED EYE)WHEN YOU GET TO Z IT BECOMES A CANARYDIAMONDMANY DIAMONDS FLUORESCE IN ULTRAVIOLETLIGHT (DOES NOT CHANGE VALUE)
CLARITY UNDER 10 POWER LOOP (TRAINEDOBSERVER WITH EXCEPTIONAL EYESITE)1. FLAWLESS/INTERNALLY FLAWLESS2. VVS-1, VVS-2,(VERY, VERY SLIGHT)3. VS-1,VS-2, (VERY SLIGHT)4. SI-1,SI-2, (SLIGHTLY IMPERFECT)5. I-1, I-2, I-3 (IMPERFECT AND VISIBLE TO THENAKED EYE)
A Good quality jewelrystore stone ‘onaverage’ is a J color, SI2 clarity with fairmake.Misleading grading is abuyer’s risk
How can the buyer know the value ofthis ‘blind’ commodity The reputation of the merchant (the average jeweler is untrained) Appreciate that the average jewelry store markup is 2-300 percent(wiggle room to haggle and price compare between stores) Certificates from reputable gem testing labs such as the GIA and andAGL (costs increase with size of stone—cost generally about 100dollars). Get a second opinion and compare prices between two or more dealers. Gem pricing guides or tables such as Rapport or the Gem guide (mostmajor jewelry stores subscribe)Selling to a ‘dealer’ is hazardous; consider getting replacement costappraisals, second opinions and look at auction houses and internet sitesPrecious gem investments carry the same risk as other tangibles and youneed to know the territory to maximize your return
Diamond GradingA GIAcertificatecosts 64 fora 1/2 caratdiamond upto 120 for a2 carat stone.
Certificated Diamonds; GIA, AGS, (EJL & IJL)are the standards for quality certificates
Examining Rough; Diamonds are Cut toMaximize Weight
The Diamond Cutters try to maximizeweight
DiamondsDiamond melee are round cut diamonds of 10 points or lessBaguettes are small step cut rectangular diamonds(both melee and baguettes are used in making jewelry)
Diamonds come in many colors and are extremely valuablewhen natural (blue, pink, yellow) and of gem qualityHope Diamond
Diamonds are often treated with heat, irradiation andeven laser. Colored diamonds are called ‘fancydiamonds’Laser, Cyclotron cause aChampaign ColorHeated to improve color
ARGUMENTS WHY TO INVEST IN DIAMONDSInflation proof like other valuables with limited supply orrarity?Portable concentrated value (can be eaten)Can be worn and shows social statusDurabilityEstate tax advantage; give to the kids or charity
ARGUMENTS WHY NOT TO INVEST IN DIAMONDSBlind commodity; you must be a dealer or know theterritory or have an agentNew mining sources for diamonds or new technology tomanufacture diamonds to challenge the cartel’s pricefixingCan get lost, stolen or exchanged by a jeweler with noway to trace it; not like a work of artEasy to buy but hard to sell
Common Diamond SubstitutesMoissaniteMoissanite is a form of silicon carbide and is usually produced synthetically.Because of its hardness (9.5 on the Mohs scale), it is perhaps the diamond imitationmaterial that is closest to the real thing in terms of durability.Although it looks quite similar to real diamond, moissanite has different physicalproperties that result in optical differences.For example, moissanite is more brilliant than diamond and also sparkles in more colorswhen light enters it.Cubic ZirconiaCubic zirconia is a form of zirconium dioxide and is created synthetically.This is one of the most popular diamond substitutes not only because it has opticalproperties similar to those of the real thing but also because it is very cheap.However, cubic zirconia is significantly softer (8.5 on the Mohs scale), and this is why iteasily accumulates scratches over time when worn. This stone is also much heavier thandiamond.
Wholesale Diamond price estimatesper carat a year ago 1 carat D/Flawless 18,360 1 carat E/Flawless 10,600 1 carat D/VVS1 12,250 1 carat J/Flawless 5,280 1 carat J/SI2 (an averagegood quality jewelrystore stone)- 3,525 1 carat M/SI2- 2,500 2 carat D/Flawless 39,000/carat
Understanding theGold, Silver andPlatinum trade
Gold Content 24 Karat pure gold (a color that cannot beduplicated) 18 Karat or marked 750 75 percent gold 14 Karat or marked 585 58.5 percent gold 12 Karat or market 500 50 percent gold Unless you have coinage or a wafer or bar ofgold, the dealer usually cheats a little on goldcontent. Many jewelry pieces are gold plated;look for the stamp.
Silver Pure silver is 99.99 percent silver Sterling Silver is 92.5 percent silver (somecopper to add strength) Coin silver is generally about 90 percent silver
Platinum and platinum groupmetals—iridium, rhodium, osmium,palladium and ruthenium Platinum is harder, more durable,hypoallergenic, lustrous, denser, scratch andtarnish resistant than gold. Look for marks that document platinumcontent Currently, it is less expensive and valuablethan gold
Gold Chains: look for Karat markings; weigh andcalculate gold or silver content; then estimate valuebased on these calculations and the gold future price
Many creative names for chain designsuch as snakes, ropes and cobra.
Many chains are made in Italy and thechain making process is quite automated.When buying, check the clasps (gold?),smoothness, workmanship and uniformity.You must distinguish plated goods or itemswith plated components from the solidgold, silver or platinum items. Offer to buya chain at 50% over the gold content priceand ignore any design features. Gold chainis gold chain and, in my opinion, brandingmeans nothing.
Gold Alloys add ColorYellow Gold (22K)Gold 91.67% Silver5% Copper 2% Zinc 1.33%Red Gold (18K)Gold 75% Copper 25%Rose Gold (18K)Gold 75% Copper 22.25%Silver 2.75%Pink Gold (18K)Gold 75% Copper 20% Silver5%
More Colors of Gold Yellow—copperGreen gold—silver, cadmiumPurple gold—aluminumLilac—zincBlue gold—ironWhite gold—primarily nickel (nickel allergies)but also some palladium and other metals Purple--aluminum and zinc
Tricolor Gold Items
Four Methods to Invest in Gold:1. Buying Scrap Gold2. Buying Gold Bullion, wafers orcoins3. Buying Gold Futures4. Buying Gold Exchange TradedFundsDiversification Only;Should you invest?
Arguments for:1. Gold is always in high demand, astandardized commodity, very marketableand portable.2. Owning gold can protect you frominflation or currency fluctuations?3. Diversification of ones portfolio is alegitimate reason to own gold ( than orequal to 8 percent).4. Gold is an excellent vehicle for protectingwealth over a long period of time?5. During a period of civil unrest it is an easyway to conceal wealth
But the supply of gold is not ‘limited’and inflation can cause old and newmines to start back into operation.Moreover, there is plenty of hiddengold in old safes, jewelry, Fort Knox,state gold reserves etc.Take the example of Silver.
Silver, Platinum and Palladium are alsosold as commodities with futures andexchange traded funds: there are daily‘spot gold, silver and platinum prices’that reflect active trading in thefutures markets
Gold is a protection from economiccollapse: high of 1800 and gold spot pricescurrently around 12-1300 dollars perounce* If you take physical possession of thegold, you are not required to pay sales taxin the State of Ohio. The dealers chargebetween 3 and 8 percent commission* To document gold content is not easy andmany pieces are gold or silver plated
If you have gold items to sell, thedealers will usually offer you anamount based entirely on gold contentand not rarity. There are someexceptions in antique gold pieces andPandas from China.
Some Basic Structural andChemical Properties of GemStones
The Mohs Hardness ScaleMineralChemical CompositionHardnessTalcMg 3 Si 4 O 10 (OH) 21GypsumCaSO 42CalciteCaCO 33FluoriteCaF 24Apatite3 Ca 3 (PO 4 ) 2 CaF 25FeldsparK 2 Al 2 Si 6 O 166QuartzSiO 27TopazAl 2 SiO 4 F 28Corundum (ruby, sapphire) Al 2 O 39Diamond10Csofthard
To give you a further frame ofreference and understand what willscratch what:On the Mohs scale:The Fingernail is 2.5The Copper penny is about 3.5A knife blade, 5.5Window glass, 6.5Steel file, 6.5
In gem stones there is a differences betweenhardness, toughness, durability, cleavageand crackingAs examples:*Sapphire is hard and durable (good fingerring)*Opal is brittle and often thin, dries out andfine opal is better worn as a pendant*Jade is tough and fibrous but only 6 on theMohs scale.
The Six Basic Crystalline Forms in GemstonesCubic, Tetragonal and Hexagonal are major gem stone structures
Three Most Common Crystalline Typesin Gemstones Cubic crystals include diamond, garnet, spineland lapis lazuli Tetragonal Crystals include Zircon Major category Hexagonal Crystals includeAquamarine, Emerald, Amethyst, Citrine(Quartz), Ruby, Sapphire and Tourmaline
Light Refraction and RefractiveIndexes: What makes stones brilliantand sparklyReflective Angle
The refractive index of a gemstone provides thesingle most important piece of information to agemologist seeking to identify an unknown stone.It is fairly constant. Gems with a higher refractive index tend toshow more brilliance, since light is bent at ahigher angle when it passes into the material.More light is then reflected back out thecrown to the eye, rather than passing straightthrough the gem.
Specific Gravity Used in identification with standards solutionsand when stone is placed in the heavy liquidsit either float or sinks to help estimate SpecificGravity Quartz specific gravity 2.66 Corundum (sapphire and ruby) is 4.00 Diamond is 3.52 Zircon, one of the densest of all gemstones,may have a specific gravity as high as 4.73
Polarization of Light; Test with aPolariscopic 1. The stone appears dark throughout a 360 rotation. The stone is isotropic (singlerefractive and cubic in crystalline structure). 2. Throughout a 360 rotation the stone blinksfour times, light and dark. The stone isanisotropic (double refractive). 3. The stone will appear light all the time. Thestone is a microcrystalline or cryptocrystallineaggregate (like, for instance, chalcedony).
Heat Treatment, Magnetism, Grit andFeel Turquois, emerald, garnet, quartz, peridot, zircon,tourmaline and topaz are likely to crack if heatedto high temperatures. Amethyst, aquamarine, zircon, tourmaline, topaz,tanzanite, sapphire may change color when heattreated. Magnetite, hematite, tourmaline and many moreare magnetic Pearls are gritty Jade feels greasy
Birefringence, Pleochroism and Play ofColors Pleochroism is caused by differing absorptionof light rays in doubly refractive crystals; maybe dichroic as in ruby that typically is orangeyred and bluish red; or trichroic such astanzanite. Play of Colors in opals A Dichroscope is used to show separatepolarized beams and identify certain stonessuch as emerald.
Color is imparted to most gem stonesby impurities (basic minerals colorless) Idiochromatic—turquois, peridot andmalachite (the material itself imparts color) Sapphire colored with iron and titanium Ruby with Chromium Amethyst with Iron Emerald with Chromium and some vanadium Tourmaline with iron and magnesium
InclusionsBeryl/Columbian EmeraldHexagonal; Sapphire
A Lapidary is an expert cutter orengraver of gemstones Gem cutters carefully study and fashion their rough stones intofinished goods to both maximize brilliance and weight because costper carat generally rises as stones are larger. Many varieties of cuts and carat sizes to accommodate the shape ofjewelry pieces. (melee, baguettes, quarters, thirds etc) Most fine gems are faceted If cut differently from the standard, gems have the term “modified”added to their names. For example, “modified round brilliant” or“modified emerald cut.” Gems cut in the brilliant style are always called brilliant cuts (forexample, “round brilliant”), while gem cuts in the step stylegenerally have specific names attached to them for exampleemerald cut, pear shape, marquise etc.
Cabochons, polished face and flat back;occasionally a Cab has an unpolished face and iscalled a drusy caba gem polished but not faceted.
COLORED STONESThe Three Major Colored Precious Stones*Rubies*Sapphires*Emeralds
Unlike Diamonds there is a Greater Variation in qualityof colored stones and no easy standards for gradingcolored stones (use a scale of 1-10?, gage color, clarity,and cut?, factor in zoning, windows and brilliance?, oruse general terms such as good, fine, gem quality etc)Thus, for the customer and the jeweler alike, theintrinsic value of a colored stone is more complicatedand difficult to ascertain. All prices are somewhatarbitrary and the per carat estimates that I will list forcertain stones are just ‘what the price has been sellingfor in the market’. In most jewelry stores, the markedprice relates to the price the jeweler paid for the stoneor piece of jewelry. Some he may have on considnment.
Even the trained-eye cannotretain color (a million hues); youneed color standards and familiaror uniform lighting in which tocompare stones. Keep a range of comparisonstones at your store and makemajor colored stones purchasesonly after you have evaluatedthem in a familiar setting
Physical and Chemical Properties ofRubies and Sapphires Both are corundum (aluminum oxide orAl2O3) which is a colorless mineral Hexagonal system (six sided crystals) Hardness 9 and toughness excellent Inclusions include “silk” or rutile needlesthat can produce a “six legged star” Burma rubies strongly fluoresce Pink sapphire name for light colors of red
Sapphires Can be and often are larger stones and pricedoes not appreciate that much with size. Titanium and iron oxide impurities produceblue sapphires Birth Stone for September Many colors; yellow, Padparadsha or hyacinth(very valuable), brown, violet, green, pink. Look at in a variety of light sources to assessbeauty and degree of inkiness (in the jewelrystore they are shown with florescent lighting)
Origins and differences between bluesapphire; subtle differences betweenorigins.Kashmir-cornflower blue and appearsleepyBurma, Thailand, CambodiaSri Lankan—lively and brilliantMontana and Australia and manycountries
Burma and Ceylon StonesSleepy cornflower blue:2 carat fine 5,000/caratLively and slightly lighterstone from Sri Lanka: fine 2carat stone- 3,500 per carat
Padparadash Sapphire: 2carat fine- 4,500 percarat
SapphireComes in Many COLORS and shadesSynthetic Alexandrite;two colors amethystto pale blue issynthetic sapphire
Both the same ‘colorless’ mineralStar Sapphire: 2 carat fine 1,200/ per caratStar Ruby: 2 carat 1,700/carat
Sapphire Treatments Less translucent and darker sapphires thatlook ‘inky’ fashioned as cabochons Synthetics sapphire made by flame fusiontechnique and is manufactured in bulk Heat-treated (majority of high quality stones) Beryllium diffusion treated--permanent(very hard to differentiate treated stonesfrom untreated stones even for an expert)
Rubies Large rubies a rarity—very few gem qualitystones over 5 carats Birth Stone for July Chromium oxide impurity General Types;1. Burma—pigeon blood (2carat- 25,000/carat)2. Sri Lanka--Rasberry3. Thailand
Rubies; cuts, sizes, differentiate from pink sapphireNo standard cut
Burma RubyStrong Florescence underultraviolet light:
Ruby Treatments Synthetic ruby can be created by severaldifferent methods including flame fusion andothers. Rubies are also subjected to moretreatments than almost any other gem. Most all are heat treated and this isundetectable and does not effect price much. Command higher prices than blue sapphire
EmeraldColor Produced by Chromium Oxide impurityThe very best and most valuable come from Columbia (Muzo &Chivor mines)African goods (more iron, darker)Distinguish from Green Beryl(Brazilian mainly)High degree of imperfection; look underthe prongs
Beryl: Be3Al2Si6O18Aquamarine; iron: 3carat-fine- 375/caratEmeraldsMorganite;lithium: 3carat-fine 125/carat
The Paradox of Aquamarine; thebathtub effect; just because it islarger does not mean that it ismore valuable. Intense smallerblue stones are highly valued
BerylThere is a differences in color intensitybetween Green Beryl (Brazil) andEmerald.AquamarineManganiteGolden Beryl
Emeralds: care, treatments andsynthetics1. Mechanical Cleaning is not recommended foremeralds. (Ultrasonic, steam, and boilingmethods can shatter emeralds)2. Oiling to improve color is a common practice3. Synthetics are expensive and hard to separatefrom natural since manufacturers can addinclusions : Emerald-- Chatham, Gilson, Linde,Russian synthetic, Emerald Hydrothermal.4. Emeralds almost always has inclusions that aretip offs to authenticity
Other Colored Stones
Quartz; most common mineral in earth’s crust:colorless, SiO2: sand in crystalline form Most common semi-precious gem stone usedin jewelry and comes in many colors Citrine, Amethyst and Rose Quartz mostcommon. Smoky Quartz, Aventurine (green) Brownish Tiger’s eye, Greyish Cat’s eye Geodes as source of quartz crystals Inexpensive
Crystalline Quartz; mostcommon mineral in earth’scrust: hexagonal, colorless (rockcrystal, most aCitrineNovemberBirthstone
AmethystQuartzFebruary BirthstoneGeodes are afavorite of rockhounds6 carat finestone- 45 percarat
Chalcedony/ Cryptocrystalline QuartzThe Rock Hound’s Quarry Comes in all colors, color banding and istranslucent Agate, Plasma, Moss Agate, Bloodstone,Carnelian, Chrysoprase, Onyx, Petrified Wood Jasper a catch all term for opaque, coloredchalcedony
Pictures of ChalcedonyChrysoprase, Carnelian, Agate
Onyx commonly carved as in chesssets etc.Black onyx with Coral
Finest Men’s RingChrysoberylAlexandrite has a changein color from red or violetto green and bluedepending on light source.Chrysoberyl Cat’s Eye(milkand honey—it winks)
Chrysoberyl Cat’s EyeBest Man’s Ring: milk and honeyeye that winksBetter than a star sapphire ordiamond
The Real Alexandrite Article
Alexandrite is a unique stone; finevarieties change color with green andreddish violet depending upon the light .Synthetic corundum sold as an affordableAlexandrite substitute and is very common inlady’s rings
Hematite; Iron Oxide, occasionally brownish redstreaks. Can be stamped or molded
Malachite (copper ore) and Pyrite(fools gold)
Rhodochrosite & RhodoniteCabochon and Beads and Carvings
Amber, Choral, Ivory, Jet & Tortoiseshell
Peridot: Attractive, Affordable, uniqueyellowish-green and DurableSoft velvety appearance, 6-7 on Mohs scale, August birthstone, andgem quality mostly come from the middle east: 5 carat fine- 235 percarat
Spodumene: Kunzite; often big stonesBeautiful pink stones like Morganite
The Feldspar Group: Moonstone,Labradorite, Amazonite, SunstoneMoonstoneAmazoniteLabradorite
Pearls Layers of nacre, calcium carbonateOrient and body colorVarious colors; pink, white, cream, blackSouth sea island pearls; white, greyish, black (Australia)Many shapes; round, pear, drop, button, baroque,Blister pearlsBiwa and fresh water pearlsNatural vs. culturedValue based on size, shape, luster, uniformityDelicate; hardness 2 and a half, acid will dissolve
Pearls; a challenge to evaluate anddeteriorate over timeBlack pearlCultured Pearls
Blue Topaz; an excellent substitute for Aqua Marine. Topaz canbe many colors including red!, pink (heat treated) and yellowPrecious topaz
Blue Topaz1. Inexpensive2. AbundantUsually irradiatedto increase color3. Eight on theMohs scale4. Has a hard lookunlikeAquamarine5. Novemberbirth stoneFine 10 carat stone- 15 per carat
Opals—Play of Color: Four basic plays; Pinfire, Harlequin,Flame and Flash with order of desirable colors-red, violet,orange, yellow, green and blueBlack Opal5-5&1/2 on Mohs scale and matrixdetermines if black or white, best in pendantsrather than ringsProblem with thin backing anddehydration with cracking.Unfavorable mythology of bad luck
Black Opal: Black or Dark Matrix with a play of colorswith blue and green being less valuable than violet,orange and red; the more colors and uniformity themore valuable the stone.
Opal Doublets and Triplets; Fine thick opal israre and blacks are very expensive
Mexican Fire and Water Opal
Jadeite andNephrite JadeComes in many colors:Mutton fatGreen apple (cheapnephrite)Purple Jade is veryvaluable but oftentreated and thisalteration is difficultto test for.Extremely tough, fibrousand good for carving,hardness 6-6
Imperial JadeVery prized byChinese Dynasties,Usually fashionedas cabochon
Turquoise(Copper AluminumPhosphate) Versatile and inexpensive
Persian Turquois,Dense, nonporousand takes high polishMore Common VarietiesAmerican or MexicanTurquois MatrixSpider web
Garnet; (the garnet group) severalspecies or a group that vary chemicallyAlmandine garnet; thetypical color in estatepiecesPyrope &Rhodolitegarnet
Garnet comes in every color except blue and thus makesfor a good January birth stone with a hardness of 7-7.5
Yellow and Green GarnetGrossularite GarnetDermatoid or GreenGarnet (pricey)
TourmalineAttractive Greenstones that are theaffordable substitutefor EmeraldsAlso have WatermelonTourmalineAnd Pink Tourmaline
Hard and durable and good as fingerringsWatermelonTypical fine green stone;chrome tourmaline: 3 caratfine stone- 575 per carat
Lapis lazuliIntense blue, lazurlitewith white (calcite)and yellow (pyrite)inclusionsFine quality fromAfghanistanGreat for carvings,necklaces andbracelets
TanzaniteComes out of theground colorless; usedto come from a singlemine in Tanzania butnow quite commonand inexpensive.It is a tricolor stonethat rivals finesapphire5 carat fine stone- 500 percarat;1 carat 350
Zircon (Zirconium Silicate) heat treated,multicolored, high refractive index and faceted likediamonds; hard but minute fractures High Refractive Index;diamond substitute.Can be any colorFine Blue Zircon:fine 3 carat stone 150 per carat
Red Spinel can compete with fine ruby; orangey redis the most valuable, but many colorsSynthetic spinel used to imitate a range of othergems.
Organic GemsOften Carved and free form Tortise Shell Ivory Jet Amber CoralChoralAmber
More OrganicsHawksbill Tortoise (anendangered species)Ivory Carving
Black StonesDiopside StarBlack DiamondObsidian(volcanicglass)
Variety of minerals that are faceted forjewelry
Some other faceted rarer gems loriteIoliteKornerupineScapolite SerpentineSpheneThomsoniteWulfenite
Artificially made stones; Goldstone isglass with copper crystals.Many imitationsand types andcolors of glass
Glass (PASTE) CRYSTAL—generally lead glass; lead content ofbetween 25 and 50 percent. Lead increase therefractive index but decreases hardness Enamel—glass fused to metal Faience—any kind of glass glaze on pottery Rhinestones---colorless glass Apache Tears---volcanic glass consisting ofrounded pebbles of black obsidian
Plastic Imitations Many types of plastics: celluloid, Bakelite,cellulose acetate, acrylic resin, melamine, urearesin and galalith Thermoplastic and Thermosetting Distinguished by feel, weight, smell, andmolding characteristics. Rarely faceted Molded interfaces
Common Plastic Imitations Coral, pearl, onyx, moonstone, cat’s eye, shell,amber, tortoise shell, ivory, and other organicmaterials. Basically, costume jewelry
Carved and Engraved Gems Cameos from shell and onyx with two differentcolor layers Pottery cameos (Wedgewood) Intaglio/engraving from hard stone ideal for aman’s ring Scarabs beetle forms Jadeite and nephrite carvings Onyx, carnelian, agate, and other chalcedoniesare most commonly carved as well as lapis-lazuliand rock crystal.
Carved and EngravedScarabCameo (conch shell)
Enamels in Jewelry: glass Cloisonné; enamel confined to cells; gold,silver and copper backing. Plique-a-Jour; lacks a metal back; stained glasswindows Champlevé; engraved metal backing An art form with many twists with brilliantresults in ornamentation of jewelry
Estate/Antique/Vintage Jewelry Evaluate like any other piece of jewelry by breaking itdown into its parts. Rarely do you pay a premium forantiquity and you have to differentiate between ‘style’and ‘fashion’. Broaches, filigree etc. Estate jewelry in the local store is usually onconsignment and the jeweler has less room to barter. The dealer in New York probably bought a sizeableestate for cash at 10 cents on the dollar. The auctionhouses are the enemy of the dealer. In the trade if you pay in cash you automatically get a10 percent discount. Many transactions are under thetable.
Auction Houses Few dedicated auction houses locally but EBTHand Cowan’s deal with jewelry Nationally there are many major auction housesincluding Bonham, Christie’s and Southeby. Most jewelers will buy from privates and you canget easily get offers for beautiful pieces or havethem sold on consignment. Each auction house has different ground rulesconcerning commissions, reserves and type ofgoods they auction. The more important thepiece, the greater interest they have.
Buying over the Internet Should have a basic knowledge about whatyou are buying and consider only those itemsthat have adequate descriptions. Certificate documentation for diamonds Try to check on the reliability of the seller You can find most anything on the internetand many items you can bid for.
Selling on the Internet Tedious and photographing jewelry is difficultTakes a good bit of time and patienceTransactional costs of packaging and shippingManaging returns and your reputationBest advice, keep your day job.
Web sites to buy and sell jewelry; Ihave no first hand experience Etsy.eBay.Art Fire.Bonanza.Zibbet
Where to buy locally For average jewelry, I would suggest Sam’s Clubor Costco as their markups are reasonable anduniform. Disadvantage is that you cannotnegotiate the fixed price and salesperson rarelyknows much about the merchandise. I do not recommend Mall shopping. It is good to establish a relationship with a localreputable jewelry store that is fair, guarantees themerchandise and is a resource for repair work.
The Appraisal Game Oftena typical jewelry appraisal is briefand not very descriptive with ambiguousterms. This may be intentional forinsurance purposes
Gold Content 24 Karat pure gold (a color that cannot be duplicated) 18 Karat or marked 750 75 percent gold 14 Karat or marked 585 58.5 percent gold 12 Karat or market 500 50 percent gold Unless you have coinage or a wafer or bar of gold, the dealer usually cheats a little on gold content. Many jewelry pieces are gold plated;
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akuntansi musyarakah (sak no 106) Ayat tentang Musyarakah (Q.S. 39; 29) لًََّز ãَ åِاَ óِ îَخظَْ ó Þَْ ë Þٍجُزَِ ß ا äًَّ àَط لًَّجُرَ íَ åَ îظُِ Ûاَش
Collectively make tawbah to Allāh S so that you may acquire falāḥ [of this world and the Hereafter]. (24:31) The one who repents also becomes the beloved of Allāh S, Âَْ Èِﺑاﻮَّﺘﻟاَّﺐُّ ßُِ çﻪَّٰﻠﻟانَّاِ Verily, Allāh S loves those who are most repenting. (2:22
Spring Volume 22 Number 3 Summer Volume 22 Number 3 Convention Volume 23 Number 1 1988 Winter Volume 23 Number 2 Spring Volume 23 Number 3 Summer . Spring Summer Fall 2015 Winter Spring Summer Fall 2016 Winter Spring Summer Fall 2017 Winter Spring Summer Fall 2018 Winter Spring Summer Fall . Author: Joan Thomas
WINTER All-Academic Team - March 19, 2013 FOR IMMEDIATE RELEASE NESCAC Winter All-Academic Team Released 871 Winter Student-Athletes Recognized for Academic Excellence HADLEY, Mass. – A total of 871 student-athletes have been named to the 2013 NESCAC Winter All-Academic Team by the conference office today.To be
1 Hot Summer/Cold Winter 1,694 4,735 4.21 4.66 2 Hot Summer/Mild Winter 1,694 3,528 2.78 3.14 3 Mild Summer/Cold Winter 1,163 4,735 3.26 3.59 4 Mild Summer/Mild Winter 1,163 3,528 2.14 2.49 5 Hot Summer/Base Winter 1,694 4,131 3.41 3.81
summer cold rain 0.05 winter hot sun 0.10 winter hot rain 0.05 winter cold sun 0.15 winter cold rain 0.20 P(sun) .3 .1 .1 .15 .65. Inference by Enumeration P(W)? S T W P summer hot sun 0.30 summer hot rain 0.05 summer cold sun 0.10 summer cold rain 0.05 winter hot sun 0.10
