Magnesio -arfvedsonite is also found at MSH, it is indistinguishable without chemical analysis. Color is dark green to gray, black. Luster is vitreous to dull. Diaphaneity is opaque. Crystal Habits include excellent prismatic crystals, prisms and pitted somewhat fibrous crystals.
Fracture is uneven to subconchoidal.
Hardness is 5 to 6. Streak is a dark blueish grey.