Diamond is lustrous because
(a) it is colourless(b) it is hard (c) it is pure(d) its refractive index is high
Answers
Answer:
b
hope it will be help to you
Answer:
refractive index is more
Explanation:
The diamond has a very bright luster because of its ability to reflect the high percentage of light that strikes its surface. The diamond has a prism like appearance, which increases the reflection of light incident on the diamond at different angles giving diamond a sparkling appearance.General
Category
Native minerals
Formula
(repeating unit)
C
Strunz classification
1.CB.10a
Dana classification
1.3.6.1
Crystal system
Cubic
Crystal class
Hexoctahedral (m3m)
H-M symbol: (4/m 3 2/m)
Space group
Fd3m (No. 227)
Structure
Jmol (3D)
Interactive image
Identification
Formula mass
12.01 g/mol
Color
Typically yellow, brown, or gray to colorless. Less often blue, green, black, translucent white, pink, violet, orange, purple, and red.
Crystal habit
Octahedral
Twinning
Spinel law common (yielding "macle")
Cleavage
111 (perfect in four directions)
Fracture
Irregular/Uneven
Mohs scale hardness
10 (defining mineral)
Luster
Adamantine
Streak
Colorless
Diaphaneity
Transparent to subtransparent to translucent
Specific gravity
3.52±0.01
Density
3.5–3.53 g/cm3
Polish luster
Adamantine
Optical properties
Isotropic
Refractive index
2.418 (at 500 nm)
Birefringence
None
Pleochroism
None
Dispersion
0.044
Melting point
Pressure dependent
Because the arrangement of atoms in diamond is extremely rigid, few types of impurity can contaminate it (two exceptions being boron and nitrogen). Small numbers of defects or impurities (about one per million of lattice atoms) color diamond blue (boron), yellow (nitrogen), brown (defects), green (radiation exposure), purple, pink, orange or red. Diamond also has relatively high optical dispersion (ability to disperse light of different colors).
Most natural diamonds have ages between 1 billion and 3.5 billion years. Most were formed at depths between 150 and 250 kilometres (93 and 155 mi) in the Earth's mantle, although a few have come from as deep as 800 kilometres (500 mi). Under high pressure and temperature, carbon-containing fluids dissolved various minerals and replaced them with diamonds. Much more recently (tens to hundreds of million years ago), they were carried to the surface in volcanic eruptions and deposited in igneous rocks known as kimberlites and lamproites.
