Testing & Determining Materials ** (It's not always practical to use these tests when you're out and about or on a piece that is not your own. Be cautious when using a test that requires heat or abrasion.)** WHAT IS IT? Is it Amber? Real Amber won't have internal bubbles and will float in very salty water. Another test is to rub the item briskly on a piece of fabric, real Amber will collect static electricity and will attract small pieces of paper. You can also sometimes get a whiff of a pine scent if rubbed briskly. Is it Bakelite? Rub the piece for a time with your fingers, Bakelite smells acidic. For pieces that don't contain stones, you can immerse it in warm water, to check the smell. Bakelite is dense and slightly heavy. Keep Bakelite away from temperature extremes. Cameo or Intaglio? A cameo is a layered design where the top sits higher in relief than it's surrounding stone or shell layers. Everything around the design is cut away. An intaglio is the opposite; the background in the highest point with the design carved into it to make a "negative" image. Is it Celluloid? Rub the piece briskly with your fingers, Celluloid smells like camphor. For pieces that don't contain stones, you can immerse it in warm water, to check the smell. Celluloid should be kept away from temperature extremes. Coral or Plastic? One test to use on a piece you already own, is to use a hot pin on an inconspicuous spot. In real Coral, the pin will not go in, on plastic it will melt into the item. Coral is porous and should have slight imperfections. Be suspicious if the item feels too smooth. Diamonds or Paste? You can usually see bubbles in paste through magnification. A real diamond will cut glass. If you test regularly, it'll be worth your while to buy a diamond tester. Are they real Gemstones? Gemstones are colder than glass. It takes practice and study to recognize specific gem cuts. Is it Gutta Percha? Rub it briskly on fabric, it'll emit a faint smell of burnt rubber. Hand-Painted or a Transfer? If a piece is painted, you should see evidence of brush strokes or sweeps of the brush. A transfer image will show tiny dots of color. You may need to look at it under magnification to see the dots. Is it Ivory? If testing a piece you already own, you can (in an inconspicuous spot) prick it with a pin that's been heated red-hot. With real Ivory the pin will make a tiny, shallow hole. Ivory has a grain that should be visible upon close examination. But some items have grain added to fool the buyer. Is it Jade? Jade should always feel cool to the touch. Paste or Glass? Using loupe or magnifier, you'll usually see bubbles in either substance. Is it a real Pearl? While Pearls have been faked since ancient times, real Pearls both cultured and natural should have a gritty texture you'll feel if you VERY LIGHTLY rub it over your front tooth. Fake pearls will feel smooth. Is the Gemstone a Doublet or Triplet? A thin layer of a real gemstone is glued on top of 1 or 2 layers of a different mineral. Doublets and Triplets are generally worth less than a single stone. They're used to enhance color or make use of a thin slice of a precious stone over a less expensive stone. Colorful Opal jewelry often uses this technique to put a dark stone behind the opal and so deepen the color. Looking under magnification, you can see the layers at the side. GOLD CONTENT Look at edges, clasps, and undersides of a piece to see if you can find markings as to gold content. To test the quality of gold, you or your jeweler will need to apply testing acids or use a mechanical tester. Metal testing kits are available through jeweler or gem suppliers and contain a stone with acid solutions used to test 10, 14, 18, & 24 Kt. Gold (in the U.S.), as well as Silver and Platinum. Some specific gold markings are listed at Buying. Gold, Gold-Plate, or Gold Fill? Gold-fill and Gold-Plate are interchangeable terms. Gold-fill is usually the method used on oldest pieces. Multiple thin layers of gold are bonded over base metal creating a thick layer of gold. Gold Fill uses a thinner layer of gold, also over base metal. For both gold-plate and gold fill, you'll need to find an appropriately inconspicuous place to scratch through the plated layer to see if there is base metal underneath or to apply testing acids. Gold-fill and gold plate will often show signs of wear through to metal underneath. TESTING FOR DIAMONDS Diamond testers are available through jeweler's suppliers, the least expensive cost around $100.00. These can sometimes be fooled by various elements; dirt on the stones, moissanite, or if you hold the tester improperly. Using a Kit To Test For Precious Metals: VERY LIGHTLY rub the item to make a mark on the stone (be careful not to damage the finish). Apply an acid solution to the mark. A mark that fades quickly shows that the piece is not the same as the quality of the acid used. If you prefer, the acid can be applied directly to the piece of jewelry. The acid will discolor the piece, so be sure to test in a spot that can be easily cleaned. **CAUTION! THE ACIDS ARE DANGEROUS IF NOT HANDLED PROPERLY!** Buying and Caring for Antique and Vintage Jewelry Buying Cleaning Gemcuts Married Pieces, Repairs & Reproductions ---I'd welcome your comments, suggestions, and any knowledge you'd care to share, as well. Is there a subject you'd like to have added to these pages? Please feel free to email me at: jthomas@jantiques.com