Thundereggs form through igneous processes. Igneous rocks form from the solidification of molten rock material called magma. This process can occur either below the Earth’s surface, forming ...

This rock recycling is a process called the rock cycle ... and glued together.Metamorphic rocks are formed from other rocks, igneous or sedimentary, which are heated and compressed underground ...

Right: OH-defects in young (0.3 Gyr) Variscan granites are one order of magnitude higher than in old (0.9-1.8 Gyr) Proterozoic granites from Scandinavia . The OH-content is reflected in recent ...