This BIG crystal of deep blue topaz is not from a common locality in Brazil, nor has it been heat-treated to get its color as many of those are. This is a natural, extremely large crystal from the Miami Mine in Zimbabwe. These were mined in the 1960s-1970s and are almost unobtainable today. A large part of this crystal is quite gemmy. The color is just terrific. This whopper crystal weighs in at 415 grams.