noun Any of several bluish-grey varieties of stone used for construction: A form of dolerite which appears blue when wet or freshly broken. Any of the several (massive) kinds of non-local stone (particularly dolerite) used to construct Stonehenge. A feldspathic sandstone found in the US and Canada. A form of limestone found in the Shenandoah Valley and some other places. A bluish-grey basalt or olivine basalt. Slate, such as comes from quarries in or near Adelaide.
noun A form of dolerite which appears blue when wet or freshly broken.
noun Any of the several (massive) kinds of non-local stone (particularly dolerite) used to construct Stonehenge.
noun A feldspathic sandstone found in the US and Canada.
noun A form of limestone found in the Shenandoah Valley and some other places.
noun A bluish-grey basalt or olivine basalt.
noun Slate, such as comes from quarries in or near Adelaide.
noun Either of two related copper- and sulfur-based bright blue stones: Copper(II) sulfate, CuSO4(H2O)x where x is 0-5, used as a coloring agent in glass-making and pottery and for other purposes. Chalcanthite, a water-soluble sulfate mineral, CuSO4·5H2O.