This exceptional crystal is a complete floater, gemmy/transparent throughout (more so in person than it appears) and is perched on a stalk of siderite. It is quite simply a world class thumbnail. In the pics you can see some of the subtle interplay of greenish, blue, and lavender color zones in the crystal, which changes depending on the lighting. It is so glassy it is almost slippery, complete all around, and a floater.