Yooperlites are a variety of sodalite-rich syenite found in the Upper Peninsula of Michigan.

Geologists recently dated the age of Watersmeet gneiss, a type of rock in the Upper Peninsula, as the oldest in the U.S. Here ...

Sodalite forms in igneous rocks that crystallized from sodium-rich ... per year on state-owned and public trust lands. Agates are formed when gas bubbles in lava leave a hole in the "vesicle" ...

"Dating zircon grains using ... techniques is now celebrated as the optimal method for determining when igneous rocks formed," the report said. The technique involves measuring the decay of ...

Granite and other rocks made from recycled magma Igneous rocks, which form from magma (which is called lava when it erupts on the surface), aren’t anything special in our solar system.

Smithsonian researchers trekked to a remote site in northern Canada to collect four-billion-year-old rock samples that could ...