feldspar, felspar Min.
(ˈfɛldspɑː(r), ˈfɛlspɑː(r))
Forms: α. 8 feldspat(h, feltspat. β. 8 fieldspar, 8– feldspar. γ. 8–9 felspar.
[The forms feldspat(h, feltspat are adoptions (the latter through Sw.) of Ger. feldspat(h, f. feld field + spat(h spar. Almost contemporaneously appear the wholly or partially translated forms field-, feldspar. The corrupt spelling felspar was introduced by Kirwan on the ground of a supposed derivation from fels, and is still more common than the correct form.]
A name given to a group of minerals, usually white or flesh-red in colour, occurring in crystals or in crystalline masses. They consist of a silicate of alumina with soda, potash, lime, etc.
| 1757 E. M. Costa Nat. Hist. Fossils 287 The opaque quartz or feldspath. 1772 tr. Cronstedt's Min. App. 8 If the characters of this field-spar are accurately examined. 1776 G. Edwards Fossilology 54 A black felt-spat..found in Sweden. 1784 Kirwan Elem. Min. 102 Sandstone mixed with mica and feltspar. 1785 J. Hutton Th. Earth in Trans. R. Soc. Edin. I. 229 Strata consolidated by feld⁓spar. 1792 Phil. Trans. LXXXII. 30 D. Hoffman discovered that red blende and feldspat were luminous when pieces of either were rubbed together. 1794 Kirwan Min. I. 317 note, This name seems to me derived from fels, a rock..hence I write it thus, felspar. 1835 Sir J. C. Ross Narr. 2nd Voy. xxix. 406 Large crystals of felspar. 1860 Maury Phys. Geog. Sea x. §494. 272 Granite is generally composed of feldspar, mica, and quartz. |
| attrib. 1807 T. Thomson Chem. (ed. 3) II. 501 The felspar glaze does not melt at the heat requisite for fusing the colours. 1830 Lyell Princ. Geol. I. 263 Traversed in all directions by veins of felspar porphyry. 1862 Dana Man. Geol. §85. 80 Feldspar-Euphotide..consisting of a minutely-granular feldspathic base with disseminated diallage or smaragdite. 1872 W. S. Symonds Rec. Rocks iv. 113 Criccieth Castle stands on a felspar rock. |
Hence
ˈfeldsparic a., resembling feldspar;
= feldspathic.
ˈfeldsparite = feldspar.
ˈfeldsparry a., containing feldspar.
| 1811 Pinkerton Petral. I. 157 Hardness, of course felsparic. 1832 Boase Geol. Cornwall 211 Felsparite or Felspar-Rock. 1852 Th. Ross tr. Humboldt's Trav. I. ii. 98 The feldsparry lavas of the Peak. |