I.D. bracelet: 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.
IGI: Stands for the
"International Gemological Institute". It is the
largest independent gem certification
and appraisal service in the United States.
Igneous: 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.
Import: The act of bringing or
carrying in goods from an outside source for trade or sale,
especially in regards to goods from a foreign country.
Inclusion: 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.
Indicolite: Blue Tourmaline.
Ingot: Metal
cast into a bar or other shape.
Inlaid: Past tense of inlay.
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 channel inlay.
Intaglio: 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.
Invisible Set: 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.
Iolite: (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.
Iridescent: A display of
lustrous rainbow-like colors. The colors seen in an oil slick or
mother of pearl are good
examples of iridescence. Synonymous with
"Pearlescent".
Iridium: 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.
Iron: 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.
Iron Pyrite: See Pyrite.
Irradiation: The process of
bombarding a gemstone with
X-rays, gamma rays or streams of subatomic particles in order to
change the stone's color.
Ivoride: See French
Ivory.
Ivorine: See French
Ivory.
Ivorite: See French
Ivory.
Ivory: A hard, smooth
yellowish-white substance made from the tusks of elephants and
walruses.
Ivory, French: See French
Ivory.
