Opaque black gemstones are a diverse group of minerals and organic materials prized for their deep, dark appearance and often high polish. These stones are popular choices in jewelry for their timeless elegance and versatility.
Among the most recognized and traditionally sought-after opaque black gemstones are treated black chalcedony (commonly known as "black onyx"), black jade, and hematite. Black onyx, a variety of quartz, is particularly well-known among lapidaries and gem cutters due to its durability and familiarity.
Common Opaque Black Gemstones
Here's a closer look at some of the prominent opaque black gemstones:-
Black Onyx (Treated Black Chalcedony)
Black onyx is a form of chalcedony, which is a microcrystalline variety of quartz. While natural onyx can be black, the uniformly black material commonly seen in the market is typically chalcedony that has been treated to achieve its consistent dark color. It is highly valued for its smooth, opaque finish and durability, making it a staple for carvings, beads, and cabochons. -
Black Jade
Black jade refers to opaque black varieties of either nephrite or jadeite. Nephrite jade is generally more common and is known for its toughness, making it highly resistant to breaking. Jadeite, on the other hand, is rarer and can exhibit a finer texture. Both types of black jade are esteemed in various cultures, particularly in East Asia, for their beauty and symbolic significance. -
Hematite
Hematite is an iron oxide mineral renowned for its metallic luster and striking dark gray to black color. When polished, it can achieve a mirror-like shine. It is denser than many other gemstones and is often used for beads, cabochons, and sculptures. Its distinctive metallic sheen sets it apart from other opaque black stones. -
Jet (Lignite)
Jet is a type of lignite coal, formed from decaying wood under extreme pressure. It is an organic gemstone, lightweight, and has a velvety, deep black color. Jet has been used in jewelry for centuries, particularly during the Victorian era for mourning jewelry. It is relatively soft and can be easily carved and polished to a high luster. -
Obsidian
Obsidian is a natural volcanic glass formed from rapidly cooled lava. Its striking black color is often accompanied by a vitreous, glass-like luster. While typically solid black and opaque, some varieties may exhibit iridescence or chatoyancy. It is used for cabochons, carvings, and sometimes in sharper forms for decorative purposes or tools. -
Black Tourmaline (Schorl)
Schorl is the most common variety of tourmaline and is typically opaque black. It often forms in elongated, prismatic crystals with distinct vertical striations. Black tourmaline is frequently used in jewelry as beads or polished cabochons and is also popular in crystal collections for its unique crystal habits. -
Black Diamond
While diamonds are primarily known for their sparkle and transparency, black diamonds are an opaque variety. Their color is due to numerous dark inclusions within the stone. Natural black diamonds are rare, and many on the market are treated to enhance their color. They are used in high-end jewelry for their modern and bold aesthetic. -
Black Spinel
Black spinel is a natural gemstone composed of magnesium aluminum oxide. It offers a deep, rich black color with a high luster, often resembling black diamonds when well-cut and polished. It is a durable and affordable alternative to black diamonds, making it an increasingly popular choice for various jewelry designs.
Summary of Opaque Black Gemstones
The table below summarizes some of the key opaque black gemstones:| Gemstone Name | Primary Composition | Key Characteristics | Common Uses |
|---|---|---|---|
| Black Onyx | Treated Chalcedony (Quartz) | Uniformly opaque black, durable, widely available | Cabochons, beads, carvings, rings |
| Black Jade | Nephrite or Jadeite | Tough, deep black, often with a waxy luster | Carvings, cabochons, beads, decorative objects |
| Hematite | Iron Oxide | Metallic luster, heavy, dark gray to black | Beads, cabochons, sculptures, magnetic jewelry |
| Jet | Lignite (Organic) | Lightweight, velvety black, easily carved | Beads, mourning jewelry, carvings |
| Obsidian | Volcanic Glass | Glassy luster, typically solid black, sharp edges | Cabochons, carvings, decorative items |
| Black Tourmaline | Complex Borosilicate | Opaque black, often striated crystals, durable | Beads, cabochons, mineral specimens, healing arts |
| Black Diamond | Carbon | Opaque, very hard, lustrous, often inclusion-rich | Fine jewelry, engagement rings |
| Black Spinel | Magnesium Aluminum Oxide | Deep black, high luster, durable, good diamond alternative | Jewelry, rings, pendants, earrings |
