gems general

Schaller argues at the outset that there is no valid scientific distinction between “precious” and “semiprecious” stones, since beauty, rarity, hardness, price, and fashion provide no consistent basis for such a division. The report then reviews U.S. gem production for 1916, valued at $217,793, an increase of 28% over 1915, with corundum, quartz, tourmaline, and turquoise accounting for most of the output. Montana again ranked first, chiefly through sapphire production, followed by California, while 34 mineral species and 79 named gem varieties were reported from 27 states. Detailed notes cover beryl, Arkansas and California diamonds, including a 1.48-carat diamond from Indiana, newly reported dumortierite deposits in New Mexico and Nevada, garnet, quartz varieties, tourmaline, and turquoise. The report also describes the gem-bearing pegmatites and tourmaline deposits of southern California and a National Museum exhibit illustrating their geology and mineral assemblages. Imports of precious stones excluding pearls were valued at $38.93 million, nearly recovering to prewar levels, and the paper concludes with a selected bibliography of recent gemological literature.