Diopside

<p>Diopside is a monoclinic pyroxene <a href="/facts/Mineral/LkUFbNmv">mineral</a> with composition MgCaSi2O6.  It forms complete solid solution series with <a href="/facts/Hedenbergite/rLoyjbnu">hedenbergite</a> (FeCaSi2O6) and <a href="/facts/Augite/7nq9ugk9">augite</a>, and partial solid solutions with <a href="/facts/Orthopyroxene/hWMTLF9o">orthopyroxene</a> and <a href="/facts/Pigeonite/LR6IKpvY">pigeonite</a>. It forms variably colored, but typically dull green crystals in the <a href="/facts/Monoclinic/5PCwXvzX">monoclinic</a> prismatic class. It has two distinct prismatic cleavages at 87 and 93° typical of the <a href="/facts/Pyroxene/hWMTLF9o">pyroxene</a> series. It has a <a href="/facts/Mohs_hardness/wXBMcVIm">Mohs hardness</a> of six, a <a href="/facts/Vickers_hardness/xz7kYRsS">Vickers hardness</a> of 7.7 GPa at a load of 0.98 N, and a <a href="/facts/Specific_gravity/ySquGd2x">specific gravity</a> of 3.25 to 3.55. It is transparent to translucent with <a href="/facts/Refractive_index/yjkzvgeE">indices of refraction</a> of nα=1.663–1.699, nβ=1.671–1.705, and nγ=1.693–1.728. The optic angle is 58° to 63°.
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Diopside open-in-new

Diopside