Pyroxenes

▪ Table

Pyroxenes

name colour lustre Mohs hardness specific gravity

aegirine green to greenish black vitreous 6 3.4–3.6

augite brown; green; black vitreous 5 1/2–6 3.2–3.5

diopside white, pale to dark green (diopside); brownish green, dark green, black (hedenbergite) vitreous 5 1/2–6 1/2 3.2–3.6

jadeite green; apple-green; emerald-green; variable vitreous 6 3.2–3.4

johannsenite clove-brown, grayish, green vitreous 6 3.4–3.6

orthopyroxene usually green; colourless, gray, yellow, brown pearly to vitreous 5–6 3.2–4.0

pigeonite brown, greenish brown, black vitreous 6 3.3–3.5

spodumene commonly grayish white; also green, lilac, yellowish, colourless vitreous 6 1/2–7 3.0–3.2

name habit fracture or cleavage refractive indices crystal system

aegirine crystals one good cleavage of 87° alpha = 1.700–1.776

beta = 1.710–1.820

gamma = 1.730–1.836 monoclinic

augite short, thick, tabular crystals one good cleavage of 87° alpha = 1.671–1.735

beta = 1.672–1.741

gamma = 1.703–1.761 monoclinic

diopside slender prismatic crystals; granular or lamellar masses one good cleavage of 87° alpha = 1.664–1.732

beta = 1.672–1.730

gamma = 1.694–1.757 monoclinic

jadeite cryptocrystalline aggregates and nodules one good cleavage of 87° alpha = 1.640–1.658

beta = 1.645–1.663

gamma = 1.652–1.673 monoclinic

johannsenite prismatic crystals and fibres in radiating, columnar, or spherical aggregates one good cleavage of 87° alpha = 1.703–1.716

beta = 1.711–1.728

gamma = 1.732–1.745 monoclinic

orthopyroxene fibrous or lamellar masses one good cleavage of 88° alpha = 1.650–1.768

beta = 1.653–1.770

gamma = 1.658–1.788 orthorhombic

pigeonite one good cleavage of 87° alpha = 1.682–1.722

beta = 1.684–1.722

gamma = 1.705–1.751 monoclinic

spodumene flattened prismatic crystals (sometimes as large as 6 ft × 42 ft); cleavable masses one good cleavage of 87° alpha = 1.648–1.663

beta = 1.655–1.669

gamma = 1.662–1.679 monoclinic

See as table:

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