Test drive·Sandbox checkout. Test cards only.

RockIDRockID

Rock guide

Common Opal

gem · common

Quick facts

Formula
SiO2·nH2O
Hardness
5.5–6.5
Luster
resinous to waxy
Colors
orange, yellow, white, no play-of-color

Common opal (potch) has no play-of-color. Fire opal is the saturated yellow-orange-red bodycolor.

Resinous silica without spectral flash and without chalcedony banding.

Scan yours

Photograph your specimen on arockid.com or in RockSnap / RockID. Three free IDs a day — no card.

Try a live scan
Coming soon on theApp StoreDownload RockSnap on the App Store — coming soonComing soon onGoogle PlayGet it on Google Play — coming soon

On the App Store, search RockSnap. Links go live when Apple and Google approve the listing. Use the web app today — same account.