combining form of THORIUM, in names of compound salts, minerals, etc., e.g., Thorogummite Min. [GUMMITE: see quot. 1889], a hydrated thorosilicate of uranium; Thorosilicate Chem., a silicate in which part of the silicon is replaced by thorium.
1889. Amer. Jrnl. Sc. & Art, XXXVIII. 481. We name this mineral thoro-gummite, because it is a gummite in which the water has been replaced by the thorite molecule. Ibid., 480. It seems better to regard the mineral as a hydrated thoro-silicate of uranium, rather than as a urano-silicate of thorium.
1909. Cent. Dict. Supp., Thorogummite … like other native compounds of thorium and uranium, has marked radio-active properties.
