gems, gems general

Sterrett’s annual review records a sharp contraction in the American gem-mining industry during 1914, reflecting depressed conditions in the gem trade and disruptions associated with the European war. The greatest decline was in Montana sapphire: important placer workings were idle and the English-owned Yogo sapphire mines closed in August. Nevada opal production also fell, while turquoise was a notable exception, increasing with the development of new deposits. The report provides detailed descriptions of numerous American gem occurrences, including agate and moss agate, amethyst, beryl and aquamarine, chrysoprase, diamonds, amazon stone, sapphire, spodumene, tourmaline, turquoise, and miscellaneous ornamental stones, with attention to geology, mining, gem quality, and commercial potential. Arkansas diamond development continued but remained inconclusive, and several diamonds were recovered from California placers. Sterrett includes a substantial historical summary of the U.S. precious-stone industry from 1882 to 1914, emphasizing its generally sporadic character and the principal roles of sapphire, turquoise, tourmaline, spodumene, and chrysoprase. A section on microspectroscopy describes its application to identifying colored gems and distinguishing ruby, sapphire, emerald, garnet, zircon, and corundum. Domestic gem production fell from $319,454 in 1913 to $124,651 in 1914, while imports of precious stones dropped to $19,211,084, the lowest value since 1908.