How do I identify Diabase?

Diabase can be identified by its Dark gray to black color. Look for these key characteristics when examining specimens.

What color is Diabase?

Diabase typically appears in Dark gray to black. Color can vary depending on impurities and formation conditions.

Diabase

A variety of Igneous

What is Diabase?

Diabase ( /ˈdaɪ.əbeɪs/) or dolerite or microgabbro is a mafic, holocrystalline, subvolcanic rock equivalent to volcanic basalt or plutonic gabbro. Diabase dikes and sills are typically shallow intrusive bodies and often exhibit fine grained to aphanitic chilled margins which may contain tachylite (dark mafic glass). Diabase is the preferred name in North America, while dolerite is the preferred name in the rest of English-speaking world, where sometimes the name diabase is applied to altered dolerites and basalts. Some geologists prefer the name microgabbro to avoid this confusion.

Uses & Applications

Diabase is crushed and used as a construction aggregate for road beds, buildings, railroad beds (rail ballast), and within dams and levees. Diabase can be cut for use as headstones and memorials; the base of the Marine Corps War Memorial is made of black diabase "granite" (a commercial term, not actual granite). Diabase can also be cut for use as ornamental stone for countertops, facing stone on buildings, and paving. A form of dolerite, known as bluestone, is one of the materials used in the construction of Stonehenge. Diabase also serves as local building stone. In Tasmania, where it is one of the most common rocks found, it is used for building, for landscaping and to erect dry-stone farm walls. In northern County Down, Northern Ireland, "dolerite" is used in buildings such as Mount Stewart together with Scrabo Sandstone as both are quarried at Scrabo Hill. The Blackbird (violin) is made of black diabase.