- The
mineral anorthoclase ((Na,K)AlSi3O8) is a
crystalline solid solution in the
alkali feldspar series, in
which the sodium-aluminium
silicate member exists...
- stratocone. The
composition of the
current eruptive products of
Erebus are
anorthoclase-porphyritic
tephritic phonolite and phonolite,
which are the bulk of...
- up to 10%. When this is
exceeded the
mineral is then
considered to be
anorthoclase. It
occurs in
granitic and
pegmatite m****es (often as the
variety cleavelandite)...
-
Euclase Eudialyte Euxenite Fayalite Feldspar Andesine Albite Anorthite Anorthoclase Amazonite Bytownite Celsian Microcline Moonstone Adularia (var.) Rainbow...
- the rock is
usually found as a
vitrophyre containing phenocrysts of
anorthoclase or sanidine.
Quartz is
found only in the most
strongly peralkaline rocks...
- An
erebus crystal is a
crystal of
anorthoclase (a type of feldspar)
found in the
immediate area
surrounding Mount Erebus near
McMurdo Station, Antarctica...
- sodalite, hauyne,
leucite and analcite) and
alkali feldspar (sanidine,
anorthoclase or orthoclase), and rare
sodic plagioclase. Biotite, sodium-rich amphiboles...
-
sanidine (monoclinic) (K,Na)AlSi3O8
microcline (triclinic) KAlSi3O8
anorthoclase (triclinic) (Na,K)AlSi3O8 Pot****ium and
sodium feldspars are not perfectly...
- in
rhyolites is
sanidine or, less commonly, orthoclase. It is
rarely anorthoclase.
These feldspar minerals sometimes are
present as phenocrysts. The plagioclase...
-
which consists essentially of alkali-feldspar (orthoclase, perthite,
anorthoclase, and albite). Some
samples may
contain a
small amount of interstitial...
