feldspar |
| noun
- (mineralogy) A large group of rock-forming minerals that, together, make up about 60% of the earth's outer crust. The feldspars are all aluminum silicates of the alkali metals sodium, potassium, calcium and barium. Feldspars are the principal constituents of igneous and plutonic rocks.
| | feldspathic |
| adjective
- (mineralogy) Containing feldspar.
| fluor |
| noun
- fluorite, Fluorite.
| fluoric |
| adjective - (chemistry) Pertaining to, obtained from or containing fluorine.
| fluorite |
| noun
- a widely occuring mineral, (calcium fluoride), of various colours, used as a flux in steelmaking, and in the manufacture of glass, enamels and hydrofluoric acid
| fool's gold |
| noun (-, sg=fool's gold)
- A mineral or other substance often mistaken for gold, mainly used for iron pyrite.
|
|