Semi-Precious Stones 187
CAIRNGORM
is the brown variety of rock crystal, also called " smoky topaz."
Cairngorm has a sentimental and historic interest involved in its use
as an ornament for the weapons and picturesque clan dress of the
Scottish Highlanders.
CARNELIAN
is a reddish variety of chalcedony, merging into greyish red, yellow,
and brown; it is translucent, like horn. Carnelian takes a high polish
and its colours are sometimes heightened by exposure to the sun or by
heat. This attractive semi-precious stone was formerly much more
extensively used than now, and its merits may, through the vagaries of
fancy and fashion, which govern the fates of all gems, again raise it
higher in popular favour. - CHONDRONITE, a mineral that is found
abundantly at the Tilly Foster mine in Brewster, Putnam County, New
York, appears in deep garnet-red crystals of great beauty. Chondron-ite
is classed with the minor gems, and it deserves a more extensive use.
Hardness, 6.5. It has a vitreous lustre.
DIOPSIDB
is a variety of pyroxene; hardness, 5 to 6; lustre, vitreous or
greasy; transparent to translucent; and doubly refractive. Pine
specimens, fit for gem purposes, are found
