Opal

Opal (az sanskr. upal — sangi qimatbaho), yak nav mineral, psev­dogidrogeli sakhti tabii. Tarkibi khpmiyaviash S1O2 • pN/); 2—14% ob dorad. Sakhtiash 5—6,5; zichiash •1800—2250 kilogramm/metr⁹. Asosan berang bu­da, vobasta ba omekhtahoi tarkibash safed, zard, bur, sabz va gayra mesha­vad. Dar tabiat yakchand kheli Opal malum ast: gialit, Opali asil, gid­rofan va gayra.

Opal dar natijai az obhoi garmi vulqonogeni takshonshavii duoksidi silisiy (ZYuz) yo dar zonai farsoish az tasiri obu oksidi karbon (IV) vayronshavii silikatho ba vujud meoyad. On dar taqniotasthoi davrahoi paleogenu neo­gen bisyor vomekhurad. Ba sifati sangi oroishi istifoda meshavad. Opali asil sangi qimatbakhost. Konhoi Opal dar Ukraina, Qazoqiston va digar joykho mavchudand.