What is Black Diamond? Definition, Usage, and Background Information
Black diamond refers to a type of gemstone that possesses an unusual property: it has been exposed to extreme pressure deep within the Earth’s crust, resulting in its unique characteristics and distinct appearance.
The Formation of Black Diamonds
The process of forming black diamonds begins millions of years ago when graphite or other carbon-rich materials are subjected to intense heat and pressure. This transformation occurs at depths of around 150 kilometers (93 black-diamond.casino miles) below the Earth’s surface, where temperatures can reach up to 3,000°C (5,500°F). Over time, the pressure and temperature conditions cause the graphite to transform into a crystalline structure that is more durable than its original form.
Properties and Characteristics
Black diamonds have several notable properties that distinguish them from other gemstones. Their coloration results from internal inclusions of other minerals or carbon-rich materials, giving rise to an opaque appearance with a distinct "matte" effect. Some black diamonds exhibit characteristic ‘inclusions’ such as tiny flakes or ‘curled tubes’, visible under magnification.
History and Discovery
The discovery of black diamond deposits has largely been attributed to geological surveys in regions known for their volcanic activity, particularly during the Cretaceous period (approximately 145 – 65 million years ago). Many ancient civilizations have long recognized the significance of these gemstones, which were often employed as symbols of power or status.
Types and Variations
While ‘black diamond’ is an umbrella term used to describe this gemstone category, variations in color intensity and internal characteristics give rise to several distinct subtypes. Some notable examples include:
- Carbonado diamonds : black diamonds with a metallic appearance
- Boron diamonds
- Diamonds displaying other dark colors (such as brown or ‘cloudburst’ gray)