Usage examples (5)

• These other forms of silica include opal, chalcedony, flint and chert (non-crystalline), and cristobalite, tridymite, coesite, and stichovite.
• But they were surprised to find cristobalite and tridymite.
• The crystals, called cristobalite and tridymite, are known to reside in comets, in volcanic lava flows on Earth, and in some meteorites that land on Earth.
• It is this high-temperature form of silica crystals, specifically cristobalite and tridymite, that Forrest's team found in planet-forming disks around other stars for...