potassic, a. Chem.
(pəʊˈtæsɪk)
[f. potass-a or potass-ium + -ic; so F. potassique.]
a. Of, pertaining to, or containing potassium or potash; = potassium in comb. Also in compounds, as mono-potassic, dipotassic; hydropotassic (combined with water).
| 1858 Mayne Expos. Lex. s.v., Berzelius termed..the combinations of the oxide [of potassium] with acids,..and of the metal with halogenous bodies, Sales potassici: potassic [salts]. 1876 Harley Mat. Med. (ed. 6) 121 Potassic Carbonate causes no precipitate. 1877 Watts Fownes' Chem. (ed. 12) I. 338 Normal potassium carbonate, or Dipotassic carbonate, K2CO3. 1906 Westm. Gaz. 7 Apr. 2/2 The Prussian Government..is a member of another ‘Kartell’—that controlling the supplies of potassic salts. |
b. Geol. Of a mineral or rock: containing an appreciable or a greater-than-average quantity of potassium, often as compared with sodium. Also applied to a metamorphic process in which such minerals are formed.
| 1903 W. Cross et al. Quantitative Classification Igneous Rocks 227 The orthoclase may be considered as wholly potassic and reckoned as pure orthoclase. 1932 A. Johannsen Descr. Petrogr. Igneous Rocks II. 63 The term orthorhyolite was originally suggested in 1919 for rhyolites whose only feldspar is potassic. 1967 Amer. Mineralogist LII. 828 The early part of the alteration sequence featured chiefly potassic metasomatism (biotite, potash feldspar), whereas the latter part was characterized by sodic metasomatism (aegirine, crocidolite). 1971 I. G. Gass et al. Understanding Earth i. 18/1 Two compositionally different feldspars, one more sodic and the other more potassic. 1974 P. G. Harris in H. S{obar}rensen Alkaline Rocks vi. i. 434/1 The anomalous 87Sr/86Sr ratios of many suites of potassic rocks suggests..a multistage origin. |