Nothing to dilute its pure seamless surface. Then there is the classy elegance of gold or silver sheen obsidian. An eye-catching glimmer on the top of the sphere, which results from tiny bubbles or crystals of muscovite, feldspar or quartz. Rainbow obsidian has its own charm. Light rose, green or cream concentric circles on the top and bottom of the sphere, caused by inclusions of feldspar, quartz, topaz or tourmaline.
Mahogany obsidian can range from nearly all rust-red to black with a touch of the rust.
The patterns of this unique and lovely sphere can be nearly as interesting as the vibrant color, which is derived from the introduction of iron oxide. It's what started me in sphere collecting. Its effect is caused by white fiber-like inclusions of cristobalite. It represents the ultimately symmetrically satisfying vision of rock. For the past seven years, I have sought to gather the largest diversity and most striking spheres from around the world.