Vote for your favorite mineral in #MinCup26! - Sphalerite vs. Anorthite Both zinc ore Sphalerite and calcium plagioclase feldspar Anorthite have perfect cleavage that will split cleanly if you hit them with a hammer, but only one can claim a larger split of your votes!
Schooner (circa 1985) says: "When the Strickland quarry was last active, the author found a boulder of cleavelandite with a small vug of aggregated lustrous white hexagonal-looking crystals with calcite and a trace of lepidolite. It was many years before the mineral was recognized as being a mica! Its unusual X-ray pattern aroused some curiosity, and it was forwarded to Pete J. Dunn at the Smithsonian. He identified it as bityite, and made an analysis by electron microprobe."
