L.
HYPERSTHENUM.
The great hardness and the specific gravity which this mineral possesses originated its name, which in Greek signifies supreme force, from νπψ, above, and σθένος, force.
This
mineral is found in crystalline masses ; it has concave breakage ; is
opaque, and found in different colours; red, dark brown,
greenish-black, and grey-black. Its cleavage is parallel to the sides.
It has a metallic light. Looked at in one direction it shows gradations
in copper-red, in golden or dark yellow ; and in another direction it
reflects greenish colours.
It marks crystal ; gives a dark green dust, and has a specific gravity of 3-38.
It melts easily. Acids do not corrode it, and it is composed of magnesia, silex, alumina, and water.
It is found in the rocks of Labrador, of Greenland, and of New Jersey.
Although used in French jewellery, the hypersthenum has never been a fashionable gem, notwithstanding its beautiful colours.
