The Laguna Verde ignimbrite ranges from dacite to rhyolite in composition, containing biotite, pumice, quartz and sanidine.
12.
Other associated minerals include nepheline, titanian andradite, aegirine, microcline, sanidine, albite, calcite, fluorite, ankerite and baryte.
13.
Other minerals in this group include adularia, anorthoclase, buddingtonite, celsian, hyalophane, microcline, monalbite, orthoclase, and sanidine.
14.
Due to the high temperature and rapid quenching, sanidine can contain more sodium in its structure than the two polymorphs that equilibrated at lower temperatures.
15.
However, U / Pb on zircon and Ar / Ar on sanidine and hornblende are the two single methods that achieve today the best results.
16.
Typical pumice contains crystals of biotite, hornblende, plagioclase, quartz, and sanidine, with minor amounts of apatite, iron oxides, and titanite.
17.
The rocks in which orthoclase ( " or sanidine " ) is present in considerable amount are leucite-trachytes, leucite-phonolites and leucitophvres.
18.
Two varieties of nepheline are distinguished, differing in their external appearance and in their mode of occurrence, being analogous in these respects to sanidine and common orthoclase respectively.
19.
Dating techniques yield different ages; the most reliable one ( argon argon dating on sanidine ) indicates that these ignimbrites were erupted 73, 000 ?23, 200 years ago.
20.
It occurs associated with hematite, magnetite, bixbyite, ilmenite, enstatite-ferrosilite, tridymite, quartz, sanidine, topaz, spessartine, beryl, mica, cassiterite and apatite.
