Opal is a hydrated amorphous form of silica; its water content may range from 3 to 21% by weight, but is usually between 6 and 10%. Because of its amorphous character, it is classed as a mineraloid, unlike crystalline forms of silica, which are classed as minerals. It is deposited at a relatively low temperature and may occur in the fissures of almost any kind of rock, being most commonly found with limonite, sandstone, rhyolite, marl, and basalt.

Gems and Minerals

Deck/File Name: Opals (opals)
Made/Donated by: Aki / Mio Color: LightSteelBlue
Released: 2021-03-06 Masterable: Yes
Wished by: saya, Frankie
Mastered by: Mio, Aki, Mysti, saya, Lina, Lex