Onyx marbles of local source are polished at Phoenix.
The gems of onyx, carnelian and agate are later and bear various figures, and in some cases Arabic inscriptions.
At one end is a remarkable stalagmitic formation of white and gold onyx, about 65 ft.
For particulars respecting the special characters, modes of occurrence and localities of the more important varieties of quartz, reference may be made to the following articles: AGATE, AMETHYST, AVENTURINE, BLOODSTONE, CAIRNGORM, CARNELIAN, CAT'S-EYE, CHALCEDONY, CHRYSOPRASE, FLINT,HELIOTROPE,JASPER, MOCHASTONE, ONYX, ROCK-CRYSTAL, SARD, SARDONYX.
Some marble is quarried at Beaver in Beaver county, and Utah onyx has been used for interior decoration, notably in the city and county building of Salt Lake City.