Mahogany obsidian stone, semi precious stone, brown, black, cabochon, stone, oval, polished, glossy shine. Measuring 25 x 18mm. Will fit in many of our 25 x 18mm mounts. The color is very delicate and will look good on many skin tones. Very beautiful brown and reddish color with black. You should expect variations in all natural, semi precious stones. No two stones are exactly alike. Sold by the piece.