2 Cubic Figure 23-1. Cubic fluorite crystal from Sterling Hill. Field of view is 1.3 mm in maximum dimension. Description Local fluorite occurs in masses, as interstitial grains in granular aggregates and as fine, small crystals in vein assemblages.
Some fluorite is violet at the contacts with nickel arsenides.
Fluorite is readily distinguished by its cleavage. Colored material is known to fade on exposure to sunlight. Where evident, the fluorescence is green to bluish green in longwave and shortwave ultraviolet and rarely vivid violet, stronger in longwave. Occurrence and paragenesis Figure 23-2. Cubic fluorite crystals with coign modifications by the trioctahedron.