On the Mohs hardness scale, a rating system used to measure the scratch resistance of minerals, obsidian as a whole ranks between 5 and 5.5. This means it is hard enough to scratch softer stones like calcite and fluorite, which have Mohs hardness ratings of 3 or below. But obsidian itself can be scratched by harder minerals like quartz, topaz, and corundum, which have ratings of 7 or higher.
The snowflake inclusions found in snowflake obsidian do not affect the overall hardness. The white specs are composed of a mineral called cristobalite, which also ranks around 5 to 5.5 on the Mohs scale. So the crystalline structures embedded within the obsidian are neither harder nor softer than the surrounding volcanic glass. The material maintains a uniform hardness throughout.
Compared to other popular gemstones used in jewelry, snowflake obsidian has hardness similar to materials like turquoise, tiger's eye, and lapis lazuli, which range from 5 to 6 on the scale. So while it is durable enough for most ornamental purposes, snowflake obsidian ranks softer than many gems like sapphires, rubies, and diamonds, which earn 8 to 10 ratings.
What does this mean in practical use? Snowflake obsidian is hard enough to withstand scratches from daily wear. But it still requires some care and protection to prevent damage. Jewelry pieces with snowflake obsidian beads or cabochons are best stored in soft fabric pouches. And they should be removed before activities that could expose them to blows, scrapes or friction against other hard objects.
For crafting and decorative uses, snowflake obsidian is hardy for indoor display pieces, carved objets d'art, countertop accents, and similar protected placements. Outdoors it can deteriorate more rapidly from weathering. And in high traffic areas where it might get knocked about, softer obsidian is more prone to chipping or fracturing compared to granite, quartzite and other tougher rocks.
Overall, while not the most robust natural stone, snowflake obsidian exhibits a medium hardness suitable for most jewelry and ornamental purposes. With proper care it can retain its distinctive beauty for many years. Just avoid exposing this glass-like material to other hard objects or high impact that could scratch or fracture its delicate snowflake pattern. And be sure to store it safely cushioned from hard knocks and bumps. Follow basic precautions, and fascinating snowflake obsidian will endure nicely to showcase its one-of-a-kind frozen landscape look.
