Large excellent crystal with a fine coating of iron oxide. Without this coating, the specimen would be waterclear. I don't know if it is possible to remove the coating, however, without damage to the crystal. There are overgrowths of Quartz clusters resembling pineapples. The third from the last photo shows an imprint from one of these clusters. A near perfect specimen which shows virtually no damage. It is nearly perfect.
Gypsum
Formula
CaSO4·2H2O
Crystal System
Monoclinic
Crystal Habit
Tabular, Crystalline - Coarse, Massive - Fibrous
Cleavage
Perfect, Distinct, Distinct
Luster
Pearly
Color
white, colorless, yellowish white, greenish white, brown