Diamond

Diamond
A clear octahedral stone protrudes from a black rock.
The slightly uneven eight-sided shape of this rough diamond crystal in matrix is typical of the mineral. Its lustrous faces also indicate that this crystal is from a primary deposit.
General
Categoryminerals
Formula
(repeating unit)
C
Strunz classification01.CB.10a
Identification
Molecular mass12.01 g/mol
ColorTypically yellow, brown or gray to colorless. Less often blue, green, black, translucent white, pink, violet, orange, purple and red.
Crystal habitOctahedral
Crystal systemIsometric-Hexoctahedral (Cubic)
TwinningSpinel law common (yielding "macle")
Cleavage111 (perfect in four directions)
FractureConchoidal (shell-like)
Mohs scale hardness10 (defining mineral)
LusterAdamantine
StreakColorless
DiaphaneityTransparent to subtransparent to translucent
Specific gravity3.52±0.01
Density3.5–3.53 g/cm3
Polish lusterAdamantine
Optical propertiesIsotropic
Refractive index2.418 (at 500 nm)
BirefringenceNone
PleochroismNone
Dispersion0.044
Melting pointPressure dependent
References[1][2]

A diamond (from the ancient Greek αδάμας – adámas "unbreakable") is a re-arrangement of carbon atoms (those are called allotropes).

Diamonds have the highest hardness of any bulk (all one type) material. Because of this, many important industries use diamonds as tools for cutting and polishing things. Many of them are clear, but some of them have colors, like yellow, red, blue, green and pink. Diamonds of a different color are called "fancies".

Big diamonds are very rare, and are worth a lot of money. Only 20% of diamonds are fit for jewellery. The other 80% are of lower quality. Those lower quality diamonds are called industrial diamonds, and are used to make things like drill bits and diamond saws. Even if a diamond is not of gem quality, it still has a value because It is very hard.

Cut and faceted diamonds can be attractive hence their use in jewellery. Diamonds are very effective electrical insulators, but also very good conductors of heat. On Mohs scale of mineral hardness, diamonds are scored as 10 (the highest score possible).

  1. "Diamond". Mindat. Retrieved July 7, 2009.
  2. "Diamond". WebMineral. Retrieved July 7, 2009.

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