Pyroxene
Videos
The pyroxenes are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. Pyroxenes have the general formula XY2O6, where X represents ions of calcium, sodi
Pyroxene (diopside) crystals from Afghanistan
Structure of pyroxene looking along the silica chains. "I-beams" are outlined in green. Silicon ions are oversized to emphasize the silicon chains.
First X-ray diffraction view of Martian soil – CheMin analysis reveals feldspar, pyroxenes, olivine and more (Curiosity rover at "Rocknest")
A thin section of green pyroxene
Basalt
Videos
Basalt; US: buh-SALT is an aphanitic extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron exposed at or very near the surface of a rocky planet or moon
Pyroxene
…before the lava erupted. The upper mantle of Earth is composed mainly of olivine and pyroxene minerals. Pyroxene and feldspar are the major minerals in basalt, andesite, and gabbro rocks. Pyroxenes are the most common single-chain silicate minerals (the only other important group of single-chain silicates…
Basalt 12
QAPF diagram with basalt/andesite field highlighted in yellow. Basalt is distinguished from andesite by SiO2 < 52%.
Vesicular basalt at Sunset Crater, Arizona. US quarter (24mm) for scale.
Columnar basalt flows in Yellowstone National Park, US