Velvet Obsidian

Velvet Obsidian is a sheen variety of obsidian, natural volcanic glass that displays a soft, satiny glow across its surface when light strikes it at the right angle. The effect resembles the nap of velvet, giving the stone its name.

The sheen is produced by countless tiny gas bubbles or aligned microscopic crystallites (microlites) frozen into the glass; they reflect light along common planes to create a gentle silvery shimmer rather than a sharp flash.

Like all obsidian it is amorphous, breaks with conchoidal fracture, and ranges from deep black to very dark grey-brown. It is closely related to silver-sheen and gold-sheen obsidian, differing mainly in the softness and color of the sheen.

Velvet Obsidian forms from rapidly chilled, silica-rich lava at or near the surface of volcanic flows and domes. Instant cooling locks the melt into glass before crystals can develop.

During cooling, immense numbers of microscopic gas bubbles and incipient crystallites become trapped and aligned along flow surfaces. When light enters the transparent glass and reflects off this dense, oriented layer, it scatters back as a diffuse velvety sheen.

Such sheen obsidian is found in major obsidian-producing regions, including Mexico and the western United States, often within the same flows that yield silver- and gold-sheen material.

Tilt the stone under a single light source: velvet obsidian shows a soft, moving silvery-grey glow rather than a mirror reflection or rainbow flash. The body is black and glassy with conchoidal fracture and sharp edges.

Hardness is 5-5.5 (scratched by steel), the luster is vitreous, the streak is white, and a thin edge transmits dark brown light.

Distinguish it from rainbow obsidian, which shows colored iridescent bands, and from labradorite, which is a crystalline feldspar (harder, with cleavage and a bright blue-green flash). Velvet obsidian's sheen is single-colored, soft, and silky, and the stone is a true glass with no cleavage.

Velvet Obsidian is prized for cabochons, beads, spheres, and carved pieces where the gentle sheen can be oriented to best effect. Cutters angle the stone so the velvety glow lies flat across the face. It polishes well but chips like all glass.

Generic obsidian has been used for millennia as cutting tools, mirrors, and ornaments.

In metaphysical traditions sheen obsidian is regarded as a grounding, protective stone said to reveal hidden truths; these associations are spiritual beliefs, not scientific facts.