zircon

n. semi-precious stone, mineral

For the spy satellite of this codename see Zircon (satellite). Zircon is a mineral belonging to the group of nesosilicates. Its chemical name is zirconium silicate and its corresponding chemical formula is ZrSiO4. Hafnium is almost always present in quantities ranging from 1 to 4%. The crystal structure of zircon is tetragonal crystal class. The natural color of zircon varies between colorless, yellow-golden, red, brown, and green. Colorless specimens that show gem quality are a popular substitute for diamond; these specimens are also known as "Matura diamond". It is not to be confused with cubic zirconia, a synthetic substance with a completely different chemical composition.
See more at Wikipedia.org...

Noun
1. a common mineral occurring in small crystals; chief source of zirconium; used as a refractory when opaque and as a gem when transparent
(synonym) zirconium silicate
(hypernym) mineral
(hyponym) hyacinth, jacinth
(substance-meronym) zirconium, Zr, atomic number 40

n. zircon, semi-precious stone, mineral

(n.)
A mineral occurring in tetragonal crystals, usually of a brown or gray color. It consists of silica and zirconia. A red variety, used as a gem, is called hyacinth. Colorless, pale-yellow or smoky-brown varieties from Ceylon are called jargon.