ˈperəˌklās, -āz noun
or peri·cla·site ˌperəˈklā]ˌsīt, pəˈriklə], ]ˌzīt\
( -s )
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 — more at halt (lame)
: native magnesia MgO in granular forms or isometric crystals (hardness 6, specific gravity 3.67-3.90)