spectral data for outcrops that identified plagioclase phenocrysts (crystals formed from volcanism), and producing digital elevation models of Mickey Buttes, which is approximately 600 meters ...

The first type, dark-toned and rich in iron and magnesium, contains intergrown minerals such as pyroxene and plagioclase feldspar ... includes plagioclase crystals within a potassium-rich groundmass.

pyroxene and plagioclase feldspar, as well as a light-toned trachyandesite with plagioclase crystals and potassium. Simulating the formation of the rocks' minerals through thermodynamic modeling ...

Pyrite commonly forms anhedral granules, with some crystals well-formed as euhedral to subhedral ... The main gangue minerals include quartz, plagioclase, potassium feldspar, and biotite. Quartz is a ...

Large plagioclase feldspar crystals can be seen below the hornblende, all embedded in a matrix of volcanic glass and feldspar crystals. Credit: Erik Klemetti Suddenly, there is a lot more color and ...

The crystals generally displayed normal tabular habits with slightly rounded edges ... inclusions in these rubies and purple sapphires are plagioclase, with the exception of one alkali feldspar ...

Potassium feldspar, ortho clays, that's the orange color. Beautiful crystals of it ... The white feldspars are plagioclase feldspar. There's a little bit of horn blend and other black minerals ...

Plagioclase crystals from the opening phases of the eruption had unique chemical zoning; the interior reflects growth in magma that was likely previously stored, while the outer zone has a ...

Quartz is found in the interstitial anhedral crystals as subgrains or recrystallized aggregates, and it is also found with a vermicular habit intergrown with plagioclase and alkali feldspar. The ...

It's this stuff, gabbro which is a very rare rock. It's basically a black granite, mostly dark colored plagioclase feldspar crystals. But the shocking thing is that the upper third of Mount Index ...