Obsidian bracelet

Obsidian is not a stone but glass. Volcanic lava that cooled so fast no crystals could form. That is why obsidian breaks with a smooth face that mirrors light instead of scattering it, and exactly why the matte and the polished version look so different while being the same material.

Matte, polished or flecked

Matte obsidian is blasted to an even, dull black that gives no light back, and is the most ordered of the three. The polished version is buffed and mirrors, which makes it stand out rather than recede. Snowflake obsidian has grey-white flecks formed during cooling, making it the least severe of the three.

Care

Because it is glass, obsidian can pick up a small chip from a hard knock against a doorframe. On the matte version, shiny spots can appear after years of wear on the points that rub most against your skin. That is wear, not a defect, and polishing does not help: you would lose the matte finish.

Combining and size

Obsidian is the neutral base of almost any dark stack. Next to hematite you get black against metallic, next to lava stone two kinds of matte. All the dark options are together in the black gemstones. It comes in 8mm and 6mm; measure your wrist and add one and a half centimetres, the breakdown is in the size chart.