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Related to K-feldspar: plagioclase, Potassium feldspar


 (kā′fĕld′spär′, -fĕl′-)
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The mineral constituents are K-feldspar (microperthite), plagioclase, quartz, riebekite, hornblende, aegirine-augite, biotite, apatite, zircon, allanite, titanite, epidote, rutile and magnetite.
Feldspars: This category included single crystals of K-feldspar, microcline and plagioclase, as well as potassium feldspar and plagioclase included in intraclasts, phaneritic rock fragments, and sedimentary rock fragments (meta-arenites).
Chemical analysis further indicated that the small amount of matrix on one side of the crystal (Figure 3) consisted of K-feldspar and iron sulphide.
Of these recipes the standard glaze (STG) and those with the wastes added as 20 percent (G1) replacing Na-Feldspar, 20 percent (G2) replacing K-Feldspar, 30 percent (G3) replacing ulexite, 40 percent (G4) replacing Na-and K-feldspar, 70 percent (G5) replacing Na-Feldspar, K-Feldspar and ulexite in the starting batch were reported hereby (Table II).
Unsystematic distribution of K2O is more likely introduced by the occurrence of minor but variable quantity of K-feldspar and muscovite.
Gold mineralization at Windfall Hills is associated with quartz stock-works and alteration zones of silica, pyrite, K-feldspar, sericite and clay.
Nevertheless, tentative counts in Table 2 show a general similarity to those reported by Dickinson and Green (1973), specimens having roughly equal amounts of quartz, K-feldspar and plagioclase.
In this granite, micas are rare and the Na-feldspar to K-feldspar ratio varies significantly (from 0.
Extensive hydrothermal alteration in the form of silicification, carbonate, hematite/magnetite and K-feldspar veins was observed in the drill cuttings.
Crystals are small (<3 mm maximum diameter) and include rounded embayed quartz, subhedral K-feldspar (anorthoclase, based on the presence of fine-scale cross-hatch twinning), and subhedral plagioclase set in a locally spherulitic groundmass of cryptocrystalline quartz and feldspar.