They found dust grains within the space rock - which fell to Earth in the 1960s - that are as much as 7.5 billion years old. The oldest of the dust grains were formed in stars that roared to life ...

Granitic rock forms at depth ... causing it to crumble into disaggregated mineral grains.

Sedimentary rocks comprise grains surrounded by water-containing pores. When rocks are squeezed together under great pressure, the grains dissolve at their boundaries into the water present in ...