¹Previous lists of this series have been given at the ends of vols. xi–xvii (1897–1916) of this Magazine. A few older names, not given in Dana (System of Mineralogy, 6th edit., 1892) or Chester (Dictionary of the names of minerals, 1896), are also included. A long list of names of gem-minerals has recently been published by W. T. Schaller (‘Gems and precious stones in 1917.’ Mineral Resources, United States Geol. Survey, for 1917, 1918, part II, pp. 147–168). Many of these are quite trivial and have been introduced solely for trade purposes. Only a selection of them, for which bibliographical references could be traced, are included in the present list. One is inclined to deal with such names in the manner of Adam Littleton, who in the preface to his ‘Latine Dictionary’ (London, 1678)writes: ‘As to the Chymical terms of Paracelsus, (which have formerly pestered Latinity) and other strange words used by men of his Tribe, which have no affinity with Latine or Greek, they are wholly omitted, and not so much as set down amongst the Barbarous.’