I.D. is short for "Identification", so an I.D. bracelet
is simply a curved plate engraved with the name or initials of the
person wearing it.
Stands for the "International Gemological Institute".
It is the largest independent gem certification and appraisal service
in the United States.
A substance produced under conditions involving intense heat, such
as that which is found in volcanoes. Igneous rock is rock formed
by solidification from molten magma.
Imperial jade is another name for emerald jade. It is a fine emerald-green
Imperial topaz is golden orange-yellow topaz; it is the most valuable
type of topaz.
Imperial Mexican Jade
Imperial Mexican jade is not jade at all; it is calcite that has
been dyed green.
The act of bringing or carrying in goods from an outside source
for trade or sale, especially in regards to goods from a foreign
Inca emerald is an emerald that is mined in Equador.
A naturally occurring flaw, (feather, fracture, fissure, carbon
spot, or cloud), within a diamond or other stone. The test for clarity
looks for these flaws.
Indian agate is another term for moss agate.
Metal cast into a bar or other shape.
Past tense of inlay.
A decorative technique in which part of the surface of a piece of
jewelry, furniture, or ceramic is cut away and stone, mother of
pearl, or some other substance is imbedded into the hollowed-out
area so that it is level with the surface of the piece. See also
Italian for "carving", an Intaglio is a carved gem wherein
the design is engraved or carved into the object so that it sits
below the surface plane of the material, as opposed to a cameo in
which the design is raised from it's background, in relief. This
technique was often used for seals, which made a raised impression
in wax used to seal a letter or authenticate a document. It was
commonly attached to watch fobs, since the watch fob is a good manner
of carrying a seal. Once seals fell out of common use, the intaglio
tended to face out to the viewer rather than down as on a seal.
Some of the most commonly found Victorian intaglios were carved
in carnelian, an orange-brown variety of chalcedony.
Intergrown crystals occur when two mineral crystals grow together
and become one.
Inverall sapphires are a type of sapphire from Inverall, New South
An investment compound is a refractory material (it can withstand
extreme heat) which is slightly porous (so that gases from molten
metal can escape) and can be formed into a mold (which will be used
in metal casting). An example of an investment compound is plaster
of paris mixed with silica, boric acid, and graphite.
An invisible (or floater) necklace looks as though the beads are
simply floating on the skin; the beads or pearls are strung far
apart from one another on an almost invisible string (like clear
A method of setting square gemstones side by side in two or more
rows within a metal border or frame so that they are flush against
one another with no metal separating them.
(also called dichroite or water sapphire). A silicate of alumina,
iron, and magnesia which is usually violet-blue, but can be deep
blue, light blue-gray, and yellow-white. Makes a beautiful transparent
gemstone which is remarkable for its dichroism.
A display of lustrous rainbow-like colors. The colors seen in an
oil slick or mother of pearl are good examples of iridescence. Synonymous
A metal of the platinum family often alloyed with platinum to improve
workability. Pieces marked "80% Plat. 20% Irid" would
indicate that the alloy is 80 % platinum and 20% iridium.
Irish diamond is not a diamond at all; it is rock crystal from Ireland.
The most common metallic element which usually appears dark brown,
from oxidation or impurity, but when pure is silvery-white. Iron
is found abundantly in nature, usually in combined forms such as
hematite, limonite, magnetite, and taconite. It is frequently alloyed
in a wide range of important structural materials like cast iron,
steel, and wrought iron. It is easily oxidized (rusted) by moisture,
and is attacked by many corrosive agents.
Irradiated diamonds are diamonds that have been exposed to radiation.
This changes the diamond's color (as the radiation changes the crystalline
structure of the diamond). The change in the diamond is permanent.
Older radiation treatments involving exposing the stone to radium;
newer treatments bombard the stone with atomic particles in a cyclotron
(which accelerates protons, neutrons, or alpha-partices to high
speeds). The irradiated stones take on a greenish or an aquamarine
hue. Irradiations of diamonds was first done in 1904 by Sir William
Crookes, who exposed diamonds to radium, giving them a permanent
greenish color; his diamonds are still slightly radioactive (at
the level of radium-painted watch). Newer irradiation techniques
bombard the crystal with atomic particles in a cyclotron, and then
the stone is heated to about 800 degrees Centigrade, producing a
stone with very little radioactivity and a permanent color change.
The process of bombarding a gemstone with X-rays, gamma rays or
streams of subatomic particles in order to change the stone's color.
Italian lapis is not lapis; it is actually blue-dyed jasper from
See French Ivory.
A hard, smooth yellowish-white substance made from the tusks of
elephants and walruses.
See French Ivory.