A bizarre and striking calcite specimen! These rhombohedral crystals, to 3 cm, grew to a certain size - then were coated with hematite - then later, began growing again, but selectively on the faces, so that on some areas there is a glassy, thin sheet over the hematite phantom inside, and on others, the hematite-coated inner crystal is exposed. These are the sorts of specimens I love to have around just to look at and to show others how fascinating crystals can be! 10.3 x 7.7 x 4.7cm