Many of the "named" cuts are little more than a minor tweek of the Tolkowsky Diamond Cut.
Properties of Diamonds
- Diamond Crystal - Isometric (Cubic)
- Crystal Habit - octahedra, cubes, elongated or flattened crystals, or flat twinned crystals.
- Luster - Adamantine; uncut crystals look greasy
- Hardness - 10, about 4.5 times harder than corundum
- Toughness - good
- Cleavage - perfect, octahedral (4 directions)
- Specific Gravity - 3.514 to 3.518
- Refractive Index - 2.4175 in sodium light. Among the highest R.I.s of any gem material.
- Birefringence - none, isotropic
- Dispersion - very high, 0.044
- Ultra Violet Fluorescence - many but not all diamonds fluoresce blue, green, yellow or reddish in both long and short wavelength u.v.light.
