Honey Calcite Rhombohedron
A finely polished honey calcite rhombohedron. Honey calcite gets its colour from impurities of hematite.
Calcite is often produced in rhombohedral shapes because that's how it breaks naturally.
This popular mineral has perfect rhombohedral cleavage, meaning the internal crystal structure has planes of weakness in three directions. When struck or cut along those planes, it breaks cleanly into rhombohedra rather than cubes or irregular fragments.
This honey calcite has an incredibly smooth texture, it's wonderfully translucent, and cloudy zoning becomes visible when it's held up to the light. This is caused by variations in impurities and tiny inclusions that were incorporated as the crystal grew.
It also shows double refraction, although it's not as clear as it would be in a colourless piece. Under a bright light or natural daylight, hold the calcite over some text, and it will appear as double vision.
Some iridescence can also be seen when the calcite is viewed from certain angles.
Calcite is a very soft mineral, so it scratches easily and must be handled carefully.
