trachytoidadj.
/ˈtrakɪtɔɪd//ˈtreɪkɪtɔɪd/ Resembling or allied to trachyte.
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the world > the earth > structure of the earth > constituent materials > rock > igneous rock > [adjective] > volcanic > trachyte
trachytic1827
trachytoid1885
1885 A. Geikie Text-bk. Geol. (ed. 2) ii. ii. v. 110 (note) For this [semi-crystalline] structure the term ‘mixed’ has been proposed, as being a mixture of the crystalline and amorphous (glassy) structures. It has been designated by Fouqué and Michel-Lévy ‘trachytoid’, as being typically developed among the trachytes.
1885 A. Geikie Text-bk. Geol. ii. ii. vii. 137 Two leading types of structure are recognised by these authors among the eruptive rocks. 1. Granitoid... 2. Trachytoid, distinguished by a more marked contrast between the crystals of the first and second consolidation, the usual presence of an amorphous magma, and the fluxion structure.
This entry has not yet been fully updated (first published 1913; most recently modified version published online December 2018).
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adj.1885