We performed experiments that demonstrate that the platy habit of spinifex olivine or pyroxene is a consequence of slow cooling of ultramafic magma in a thermal gradient (7–35°C/cm). The charges were ...

Olivine, pyroxene, plagioclase, hornblende, and magnetite ranging from a few millimeters to centimeters are common megacrysts. These megacrysts are usually ejected from the volcanic vent as the cores ...

However, looking at light reflected by the asteroid to deduce its composition – rich in pyroxene but low in olivine – revealed that it does match samples from the moon collected by the Apollo ...

In this case the olivine crystals formed early in the crystallization history but also at elevated temperatures. Pyroxene oikocrysts show distinct zoning from pigeonite to augite, i.e. from Ca-rich ...

Seawater seeps down into the mantle and heats up. As the seawater hits the minerals, the olivine and pyroxene within the periodite turn into serpentine minerals and produce hydrocarbons.