The experience of exploring the Brushy Creek mine in Missouri for calcite crystals is recounted. The lead mine was discovered to contain large deposits of calcite in the late 1970s, and lots have been sold to collectors and mineralogists since the mid-1990s. The largest crystals are above and around a lake 1,100 feet underground. Collectors hoping to use this location for making substantial profit must include costs for labor, housing, food, transportation, equipment, supplies, and insurance in ...