Chemical composition:
Pyroxene is a group of silicate minerals, composed of varying amounts of silicon, oxygen, aluminum, iron, magnesium, calcium, and other elements.
The most common pyroxene minerals are enstatite (MgSiO3) and diopside (CaMgSi2O6).
Physical properties:
Color: Pyroxene can vary in color from black, green, brown, gray, to white.
Luster: Pyroxene can have a vitreous, dull, or metallic luster.
Transparency: Pyroxene can be transparent to opaque.
Crystal habit: Pyroxene typically forms as prismatic or elongated crystals, sometimes with a square or rectangular cross-section.
Hardness: Pyroxene has a Mohs hardness of 5-6.
Specific gravity: Pyroxene has a specific gravity of 3.2-3.6.
Cleavage: Pyroxene has two directions of perfect cleavage at about 87 and 93 degrees.
Fracture: Pyroxene has a conchoidal to uneven fracture.
Magnetic properties: Pyroxene is not magnetic.
Thermal conductivity: Pyroxene has a low thermal conductivity.
Optical properties:
Refractive index: Pyroxene has a refractive index of 1.65-1.69.
Optic sign: Pyroxene is biaxial negative
Dispersion: Pyroxene has a moderate dispersion.
Pleochroism: Pyroxene exhibits strong pleochroism, with different colors appearing in different orientations.
Birefringence: Pyroxene has a moderate birefringence of about 0.009.
Extinction: Pyroxene has an extinction angle of about 20-30 degrees.
Interference colors: Pyroxene typically exhibits first-order gray or yellow interference colors.
Relief: Pyroxene has a moderate relief.
Optic axis: Pyroxene has two optic axes.
Please note that these properties can vary depending on the exact composition and impurities present in the mineral specimen.
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