Four Geological Formation Paths

Groundwater dissolves silica → precipitates in rock fractures. Growth rates:1-10mm/day(not per century). Only 0.1% veins yield gem clarity.

Silica-rich vapors cool into opal (in seawater) or sulfur crystals (with acidic gases).

Plate collisions submerge quartzite → recrystallize at 300°C/5 kbar. Himalayas produce <1 ton/decade.

Meteoritic silica fuses at 1,600°C (not 3,500°C) into moldavite. Magnetic anomalies confirm cosmic origin.