Opal
Hydrated silica, softer and lighter than the quartz family, and the only common material that can dry out and crack years after you find it.
6 entries, each with field marks, look-alike tells, and what the collecting rules actually say.
Boulder Opaluncommongemstone · Mohs 5.5-6.5black, white, gray
Common Opalcommonmineral · Mohs 5.5-6.5white, gray, yellow
Fire Opaluncommongemstone · Mohs 5.5-6.5red, orange, yellow
Hyalitecommonmineral · Mohs 5.5-6.5colorless, white, yellowish
Opalcommonmineral · Mohs 5.5-6.5white, black, colorless
Precious Opalraregemstone · Mohs 5.5-6.5white, black, blue
Find opal near you
RockHoundR maps real collecting spots, what each one produces, and the land status, so you know before you drive.
