You can use apps like "Rock Identifier ... the healing power of crystals and want to see if the ones you're finding are good ...

Large crystals found in geodes and other rocks are relatively rare. Pink ChalcedonyA pink chalcedony shows off its beauty. Chalcedonies include many types of cryptocrystalline quartz gems and ...

That’s par for the course on the red planet, but there was something very different about this rock. It had a surprise inside: pure sulfur crystals ... by the find. The presence of sulfates ...