"The Mystery of Lyle and Louise"

Brown, fluorescent crystals intergrown in dolomite rock.

Red, earthy, in natural chunk form; common pigment ore.

Pure translucent to white, rhombic cleavages, Mohs’ hardness of 3.

Pure, large, transparent-to-translucent cleavages, Mohs’ hardness of 4.

Brown, earthy, massive; used for yellow pigment.

Nearly pure, green crystalline forsterite.

Light pink, massive, crystalline, translucent.

When minerals, rocks, and fossils cannot be accurately identified by macroscopic observation and testing, thin section slides can reveal the composition and structure of the specimens on a microscopic level.

Light gray, compact, hard, opaque, microcrystalline silica mineral.

Utah