Jasper, a form of chalcedony, is an opaque, impure variety of silica, usually red, yellow, brown or green in color; and rarely blue.

It has flourishes that include electric window shades (both the blackout and opaque varieties) for the 35 windows, which do all sorts of neat things, like lower when the sun swings to the west each afternoon and then raise themselves 10 minutes before sunset.

This principle is questionable when it comes to more opaque varieties of literary language, where the writer tends towards the innovative techniques of poetry.

Garnet species' light transmission properties can range from the gemstone-quality transparent specimens to the opaque varieties used for industrial purposes as abrasives.

A very dark brown to black opaque variety is known as morion.

When iron content is high it is an opaque black variety, marmatite.

The darker more opaque varieties contain more iron.

Instead of ordinary carbon, I used the mineral carbonado, an opaque variety of diamond.

Whether you wore the glittery, perforated version in the '80s, or prefer the opaque ballet flat variety today.