The rarest gemstone in the world is considered to be ... of 5.5. It formed deep underground in a pegmatite — an igneous rock. Its chemical formula is Bi³⁺Sb⁵⁺O₄ with traces of tantalum.

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 ...

The world's rarest gemstone is made of kyawthuite ... Investigations revealed that it likely formed deep underground in a ...

Silent auctions added an extra layer of excitement, as attendees placed their bids on rare and unique pieces, hoping to take ...

PT Rocks and Gems, which offers crystals, stones, jewelry and decor, has opened in the Crossroads Center Mall. Owner Phil Barrett operated a seasonal booth at the mall and visited statewide events ...

Evidence for the use of rock crystal - a rare type of perfectly transparent quartz which forms in large hexagonal gems - has occasionally been found at prehistoric sites in the British Isles, but ...