This specimen is a large 3-dimensional knob that USED to be calcite but has now been entirely converted into sparkly purple fluorite. The color stinks in the photos but in person it IS rather purple, I assure you. It also is prettier. The calcite scalenohedrons are small, to 1 cm, and in person you can see tha tht especimen is literally made up of them though here it looks like a lump. BETTER In PERSON! I think, given the size and condition of the specimen, that this is a really significant piece!