Description:An unusual igneous rock formed from molten magma that solidified within the Earth's crust. This rock is composed of the mineral dolomite (brownish) and an amphibole, richterite (black). The rock has a gneissic fabric, indicating that it has been deformed by forces acting within the Earth's crust.
Representing:An igneous intrusion into the Canadian Shield, of unknown age.
Original location:Blue River, British Columbia
Estimated mass (tonnes):5.4