9.3" Sparkling Quartz Chalcedony Stalactite Formation - India
This is a gorgeous, 9.3" wide, sparkling chalcedony stalactite formation, collected from Maharashtra, India. This specimen would have formed from the ceiling of a cavity within the host rock.
Chalcedony is any microcrystalline variety of silica composed of very fine intergrowths of quartz and moganite. Microcrystalline meaning the crystals are microscopic and cannot be observed by the naked eye. Both quartz and moganite have the same chemical formula SiO2 (silicon dioxide) but different crystal structures. When free from impurities, chalcedony is colorless and transparent. Dependent on impurities present during formation, chalcedony can form in a wide variety of colors including red, yellow, green, blue, purple, grey, white and numerous color hues in between. Chalcedony is quite hard, being a 7 on the Mohs Hardness Scale, which makes sense considering quartz is the benchmark mineral for a 7.