periclase
noun
peri·clase
ˈperəˌklās,
-āz
variants or periclasite
ˌperəˈklā|ˌsīt,
pəˈriklə|,
|ˌzīt
plural -s
: native magnesia MgO in granular forms or isometric crystals (hardness 6, specific gravity 3.67–3.90)
Word History
Etymology
periclase from German periklas, modification of Italian periclasia, from Greek periklasis act of twisting or breaking around (from periklan to twist around, break around—from peri- + klan to break—+ -sis) + -ia -y (from Latin); periclasite from periclase + -ite (lame)