Glossary
A
Alloy-a mixture of different metals. Usually done to create a more desireable trait in a metal--for instance, to make it harder.
Annealing-The process of heating metal (jewelry metals until red hot usually) for a period of time to release the molecular changes created when it has been hardened either through work hardening or heat hardening.
Asterism-The "star" effect that some gemstones display when moved in relation to a light source. Sapphire and ruby are particularly noted for having this effect in some examples.
Aventurine-Click here for information on Aventurine.
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B
Bail-The portion of a pendent through which the chain or necklace passes.
Bangle-A bracelet variety designed to slip over the hand which moves around freely on the wrist. Often, several are worn at once so that they make noise when they bang together.
Bezel-A style of stone setting in which a strip of metal completely encloses the outer edge of the stone securing it in place.
Brass-Alloy of copper and zinc with a pretty yellow color. This alloy naturally oxidizes green.
Bronze-Alloy of copper and tin with varying percentages. This alloy has been used since ancient times for coinage, sculpture, weapons as well as jewelry. This alloy oxidizes in various manners depending upon environment it is exposed to.
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C
Cabochon-A stone that has been cut into a shape with a flat bottom and a rounded top.
Casting-Filling a mold with molten metal to produce a form. Some metals can be poured into a mold, while others need to be forced into it through various methods such as spin casting, vaccuum casting, or steam casting.
Channel Setting-A style of stone setting used for faceted stones in which channels are created in parallel strips, where the girdles of stones will fit. Creates a clean line of stones.
Cleavage-This is a term to describe the property that some minerals have of tending to split along clean planes in one or more directions. Not all minerals have this property, and many have it in several different directions. Cleavage properties are related to molecular structure.
Crazy Lace Agate-Click here for information on Crazy Lace Agate.
Crown-The upper portion of a faceted stone from the girdle up to the top of the stone.
Crystal-A homogeneous solid with a distinct internal molecular structure. All minerals have a particular crystal structure based on their molecular makeup. Crystal is also a term used for glass impregnated with lead.
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D
Dalmatian Jasper-Click here for information on Dalmatian Jasper.
Dispersion-The division of white light into its various component colors.
Dopping Wax-A hard wax used to attach the dop stick to the stone to be cut.
Dop Stick-Sometimes just called a dop. A small stick or dowel on which stones are mounted temporarily so they can be secured for cutting.
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E
Enamel-A mixture of glass and metal oxide (for colors), which is fused in a kiln to metal surfaces.
Engraving-Incscribing metal or other materials using a sharp blade sometimes called a scriber. Engraving machines are used for letters and numbers.
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F
Faceted Stone-A stone that has been precisely cut into angular planes to facilitate the scattering and return of light to the viewer's eye.
Flux-A substance applied to metal prior to brazing or soldering which cleans the metal and creates a coating on the surface to protect it from reoxidizing during the process.
Fracture-The manner in which a stone breaks.
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G
Girdle-The outermost edge of a faceted stone which divides the crown from the pavilion.
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H
Hardening, Work-Making metal stiffer by working it with bending or hammering. Most metals will change at the molecular level when it is worked in this manner.
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I
Inclusion-An internal flaw within a stone. Often inclusions are small mineral crystals.
Investment-A powder of plaster and silica used to create molds for casting. Also the process of creating such a mold.
Iridium-A rare earth metal often alloyed with Platinum for jewelry at either 5 or 10 percent to raise the its hardness. Interestingly, Iridium is thought to be more common in extraterrestrial matter than on Earth, and is the most important piece of evidence linking the extinction of the dinosaurs with an asteroid strike because of its high concentration in the K-T boundary which occurs in the rock formations from the end of the Cretaceous Period.
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J
Jadeite-Click here for information on Jadeite.
Jump Ring-A wire circle with a split in it. Often used to attach clasps on chains or to attach ear wires to earrings.
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K
Karat-A measure of the fineness in gold. 24 karat gold is pure gold, while any lower karat value indicates an alloy with other metals. 18 karat gold is 18/24 gold or 3/4 or 75% gold with 25% other metals added. 14 karat is 14/24 gold or 7/12 or roughly 58% gold. Gold is alloyed with other metals to alter its color or make it harder and less easily scratched.
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L
Labradorite-Click here for information on Labradorite.
Lapidary-The art of cutting stones. Sometimes used to refer to the one cutting the stones, although a more common term for the cutter is lapidary artist.
Live of Sulfer-A chemical used to oxidize silver and copper.
Lobster Claw-A type of chain clasp that looks like a lobster's claw. This type is relatively popular because it is durable and easy to hook.
Leopardskin Jasper-Click here for information on Leopardskin jasper.
Lost Wax Casting-A process of casting that follows these steps:
- A wax model is made of the intended final piece.
- With wax sprue wires, it is attached to a wax base.
- A container (flask) is placed around it, and a plaster of paris type substance, called investment, is poured around it and allowed to set up.
- The flask is placed in a kiln to burn our the wax, leaving a mold of the intended piece.
- Hot metal is poured or forced into the empty mold, leaving a duplicate of the original wax.
Luster-Generally refers to the manner in which light reflects from the surface of a gemstone. Some typical descriptors include: metallic, non-metallic, waxy, silky, or greasy, among others.
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M
Malachite-Click here for information on Malachite.
Mariam-Click here for information on Mariam.
Matte Finish-A surface finish created by sandblasting or brushing that has a soft dull look.
Mohs Scale of Hardness-A scale developed by Friedrich Mohs to measure the hardness of minerals in a relative manner. The scale ranges from 1 to 10, with 1 being the softest, and 10 being the hardest. Diamond has a hardness of 10, with no known mineral able to scratch it. Talc has a hardness of 1 being very soft. Quartz, a common mineral, has a hardness of 7. Window glass has a hardness of 5.
Montana Agate-Click here for information on Montana Agate.
Mokume-Gane-A technique developed by the Japanese in which multiple layers of different metals are fused together, and then the resulting sheet is punched and filed to produce interesting patterns.
Mookaite-Click here for information on Mookaite.
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N
Nickel Silver-An alloy which usually consists of a mixture of Nickel, Copper, and Zinc. Nickel silver does not contain any silver at all, and it was developed to imitate the color of Silver. Various percentages of the above metals could all be termed Nickel Silver.
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O
Oiled-A process in which a stone is soaked in some type of oil to enhance its luster and hide imperfections. This is frequently done to Emeralds because of their fractured nature.
Oxidation-A discoloration that forms on the surface of many metals as the molecules bond with atmospheric Oxygen. Iron oxide is rust. Silver oxide is tarnish.
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P
Pavé-A method of setting faceted stones to produce a look on the piece of jewelry of being covered completely with stones. Basically paving the surface with stones.
Pavilion-The bottom portion of a faceted stone from the girdle of the stone to the bottom point or culet.
Pickling-Placing metal to be cleaned into a dilute solution of sulphuric acid.
Piercework-Cutting holes in metal with a jeweler's saw to create intricate patterns. This is sometimes confused with filigree, which is fine wires soldered together to create intricate patterns.
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Q
Quartz-One of the most abundant minerals in the Earth's crust. Its chemical formula is SiO2. It forms six-sided crystals and has no cleavage. It has a moh's hardness of 7. It has many varieties including Amethyst, Citrine, Smokey Quartz, Rose Quartz, Chalcedony, and Tiger's eye among others. Chalcedony in particular has many sub-varieties.
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R
Refractive Index-Measure of how light is sent back to the eye from the stone. A higher refractive index indicates a brighter stone. Some stones are doubly refractive, which means that they split light into two different paths. Calcite is an example of double refraction; in very clear rhombs, it will double letters on paper if read through.
Rhodochrosite-Click here for information on Rhodochrosite.
Rock Crystal-Colorless variety of quartz.
Rough-Minerals or rocks in their natural state that have not been cut.
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S
Signet Ring-A ring with a design cut into it which can be impressed into hot wax. In older times, it was used to seal and verify that correspondence was from who one thought it was from.
Silver, Coin-In the past when Silver coins were destined for actual circulation, they were typically minted with a mixture of Silver and other metals to harden them so they would stand up to everyday use. Typically the percentage of silver was around 87-90% Silver. Consequently, mixtures in this range have become known as coin silver.
Silver, Fine-Silver (Atomic symbol Ag) is a white metal commonly used for jewelry. The designation "fine" indicates that the metal has been purified as much as possible. It is sometimes called .99 fine.
Simulant-A material used to imitate a particular gemstone. Different colors of glass have been used for many years to imitate various gemstones. Famous diamond simulants include YAG (Yttrium Aluminum Garnet), CZ (Cubic Zirconia), and recently Moissanite.
Slab-A slice of rock or mineral from which cabochons are traced out and cut.
Slab Saw-A diamond saw designed to cut slabs from rough material. Typically they use oil as a coolant.
Specific Gravity-A ratio of weight to volume. Specific gravities are calculated in relation to water's specific gravity which has a value of 1. A material with a specific gravity of 3 is 3 times as heavy as an equal volume of water, while a material with a specific gravity of .5 is half as heavy as an equal volume of water.
Sprue-Metal bar attached to casting left from the channel used to allow metal into the mold.
Synthetic stone-A manmade gemstone which is chemically identical to a natural stone. Typically synthetics have fewer or no flaws unlike natural gemstones. Synthetics tend to be less expensive than naturals.
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T
Titanium-A strong, light metal (Ti) more and more frequently used in jewelry. It is grayish in color and occurs as a native element.
Torque-A open ended neck ring popular in ancient times, particularly among Celtic peoples. Sometimes the word is spelled "Torc."
Translucent-A gemstone characteristic where some light is able to pass through the stone, but it is not clear enough to see through.
Transparent-A gemstone characteristic where light passes freely through the stone, and objects can be clearly seen through the material.
Trim Saw-A small diamond wet saw used to rough out the shape of cabochons prior to grinding them into final shape.
Turquoise-Click here for information on Turquoise.
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U
Ultraviolet light-Light energy that is not visible to the human eye, and which has very short wavelengths. Many minerals display fluorescence under this type of light.
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V
Vermeil-Gold covering a less precious metal, usually sterling silver.
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W
Welding-The process of fusing two pieces of metal together by melting the contact points.
White Gold-Gold that has been alloyed with metals such as Nickel or Zinc to bleach out the gold color.
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X
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Y
YAG-An abbreviation for a diamond simulant. This stands for Yttrium Aluminum Garnet, a synthetic substance.
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Z
Zinc-A metal (atomic symbol Zn), which is used in many applications including United States Pennies, galvanizing steel to prevent rust, and for pigments in paint. It is less commonly used in jewelry applications except as a component of alloys.
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©copyright Chad Parker, 2005, 2006, 2007