carbonado
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Carbonado, commonly known as black diamond, is one of the toughest forms of natural diamond. It is an impure, high-density, micro-porous form of polycrystalline diamond consisting of diamond, graphite, and amorphous carbon, with minor crystalline precipitates filling pores and occasional reduced metal inclusions. Titanium nitride (TiN, osbornite) has been found in carbonado. It is found primarily in alluvial deposits where it is most prominent in mid-elevation equatorial regions such as Central African Republic and in Brazil, where the vast majority of carbonado diamondites have been found. It
Key facts
- Mineral.name
- Carbonado
- Mineral.category
- Native minerals
- Mineral.boxbgcolor
- 3F4040
- Mineral.boxtextcolor
- fff
- Mineral.image
- Carbonado diamondites Bangui region, Central African Republic.jpg
- Mineral.alt
- Sometimes cut as gemstones - often requiring lasers -, but have a granular appearance. Usually cracked in high-pressure presses for industrial usage.
- Mineral.caption
- Three carbonados from the Central African Republic
- Mineral.formula
- C
- Mineral.color
- Typically black, can be grey, various shades of green and brown sometimes mottled.
- Mineral.habit
- Polycrystalline
- Mineral.system
- Isometric-hexoctahedral (cubic)
- Mineral.fracture
- Irregular torn surfaces
- Mineral.mohs
- 10
- Mineral.luster
- Adamantine
- Mineral.polish
- Adamantine
- Mineral.opticalprop
- None
- Mineral.birefringence
- None
- Mineral.pleochroism
- None
via Wikipedia infobox
Wikidata facts
- Image
- Carbonado diamondites Bangui region, Central African Republic.jpg
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- Commons category
- Carbonado (mineral)
Sources (1)
via Wikidata · CC0
~7 min read
Article
8 sectionsContents
- Unusual properties
- Toughness vs. hardness
- Hypotheses for origin
- Extraterrestrial origin hypothesis
- Largest cut diamond
- See also
- References
- External links
Carbonado, commonly known as black diamond, is one of the toughest forms of natural diamond. It is an impure, high-density, micro-porous form of polycrystalline diamond consisting of diamond, graphite, and amorphous carbon, with minor crystalline precipitates filling pores and occasional reduced metal inclusions. Titanium nitride (TiN, osbornite) has been found in carbonado. It is found primarily in alluvial deposits where it is most prominent in mid-elevation equatorial regions such as Central African Republic and in Brazil, where the vast majority of carbonado diamondites have been found. Its natural colour is black or dark grey, and it is more porous than other diamonds.
== Unusual properties == Carbonado diamonds are typically pea-sized or larger porous aggregates of many tiny black crystals. The most characteristic carbonados are mined in the Central African Republic and in Brazil, in neither place associated with kimberlite, the source of typical gem diamonds. Lead isotope analyses have been interpreted as documenting crystallization of carbonados about 3 billion years ago; yet carbonado is found in younger sedimentary rocks.