Calcite on Heulandite, Mirzapur, Uttar Pradesh, India. Feather-shaped translucent yellow calcite crystals up to 16 mm long on pink heulandite crystals up to 2 mm. The calcite crystals have unusual triangular cross-sections.
Mexican Amethyst This beautiful amethyst specimen is from a mine in Guerrero, Mexico. Photo by Robert WeldonGIA, courtesy Gem & Mineral Department, Natural History Museum of Los Angeles County. Visit Amazing Geologist for more.