*Quartz-
| SiO2
- Occurs as chalcedony (blue, white, brown, colorless) in veins up to about 12-inches thick with some smaller veins consisting of banded light blue agate.
Crystalline quartz is also present, with some crystals showing zoned, light-colored amethyst terminations.
The most notable quartz occurence are the chalcedony pseudomorphs after melanophlogite [46SiO2 · 6(N2,CO2) · 2(CH4,N2)] in open cavities within the chalcedony veins.
The individual pseudomorphs show cubic morphology, occuring as crust-like aggregates (most common),
sharp cubes (some isolated on the matrix) and complex intergrown cubes showing a stepped repeating pattern on the cube faces.
The pseudomorphs range in color from blue to white to colorless and range in size from about 1 to 8 mm. |