Both black onyx and black obsidian are captivating dark gemstones, often mistaken for one another. However, these stones possess distinct characteristics that set them apart in terms of formation, properties, and even perceived energy. This comprehensive guide will delve into the key differences, helping you understand which stone resonates most with you.
What is Black Onyx?
Black onyx is a variety of chalcedony, a cryptocrystalline form of quartz. This means it's composed of microscopically small quartz crystals, resulting in a dense, opaque stone. Its deep black color is often attributed to the presence of trace elements and impurities within its structure. Unlike obsidian, onyx is formed through a process of sedimentary deposition within rock cavities. Over time, layers of silica build up, creating the characteristic banded structure often visible in onyx varieties (though less so in black onyx).
What is Black Obsidian?
Black obsidian, on the other hand, is a volcanic glass. It forms when molten lava cools rapidly, preventing the formation of crystals. This rapid cooling results in a smooth, glassy texture, unlike the slightly more granular feel of onyx. The intense black color of obsidian stems from its minimal mineral content. The lack of crystal structure is a key differentiator.
Black Onyx vs. Black Obsidian: Key Differences Summarized
| Feature | Black Onyx | Black Obsidian |
|---|---|---|
| Formation | Sedimentary deposition of silica | Rapid cooling of volcanic lava |
| Composition | Cryptocrystalline quartz (chalcedony) | Volcanic glass |
| Texture | Slightly granular, can have banding | Smooth, glassy |
| Hardness | 6.5-7 on the Mohs scale | 5-5.5 on the Mohs scale |
| Luster | Waxy to vitreous | Vitreous |
| Transparency | Opaque | Usually opaque, sometimes translucent |
| Specific Gravity | Slightly higher than Obsidian | Slightly lower than Onyx |
How Can You Tell the Difference?
Distinguishing between black onyx and black obsidian requires a keen eye. Here are some practical tips:
- Texture: Run your finger across the surface. Obsidian will feel smoother and more glassy than onyx. Onyx will have a slightly more granular, almost velvety texture.
- Luster: Obsidian exhibits a brighter, more pronounced vitreous (glassy) luster compared to onyx's slightly waxy luster.
- Hardness: While a definitive hardness test requires specialized tools, you might notice a slight difference in resistance to scratching (though you shouldn't try to scratch them!). Obsidian is generally softer than onyx.
- Banding: Though less common in black onyx, some specimens may show subtle banding. Obsidian lacks any banding.
- Fluorescence: Under UV light, Obsidian sometimes exhibits fluorescence, a property usually absent in Onyx.
What are the Properties and Uses of Black Onyx and Black Obsidian?
What are the properties and uses of Black Onyx?
Black onyx has been prized for its beauty and purported metaphysical properties for centuries. It's often used in jewelry, carvings, and decorative objects. Many believe it to be grounding and protective, helping to dispel negativity.
What are the properties and uses of Black Obsidian?
Black obsidian is also popular in jewelry and decorative arts. Known for its sharp edges, it's also used in some tools. Metaphysically, it's associated with protection, grounding, and truth-seeking. Its sharp edges symbolize the cutting away of negative energies.
Are Black Onyx and Black Obsidian Expensive?
The price of both stones varies depending on factors like quality, size, and the type of jewelry or object they're used in. Generally, high-quality, well-cut pieces of both stones can be relatively expensive.
Where can I buy Black Onyx and Black Obsidian?
Both stones are widely available from jewelers, online retailers, and metaphysical shops. Be sure to buy from reputable sources to ensure authenticity.
This detailed comparison provides a clearer understanding of the distinct qualities of black onyx and black obsidian. Remember that visual inspection, combined with understanding the formation and properties of each stone, is the best way to tell them apart.
