Cov khoom siv crystalline silicon yog cov khoom siv hluav taws xob tseem ceeb tshaj plaws, uas yog grey-dub khoom nrog cov xim hlau ci, siab melting point (1410), siab hardness, brittleness, thiab tshuaj inactivity nyob rau hauv chav tsev kub. Nws txoj kev lag luam feem ntau yog ntau dua 90 feem pua , thiab nws tseem yuav yog cov khoom siv tseem ceeb rau hnub ci hlwb rau lub sijhawm ntev yav tom ntej.
