What is diabase?
Answer Hi Ed, Diabase is a type of rock. If you’ve ever heard of GABBRO it’s the same kind of rock but with a slightly different mineral composition. That might not help much so let’s describe it. A Diabase is black to dark gray to dark green rock that is made up of crystals large enough to see with the unaided eye. It’s made of minerals heavy in iron like magnetite, augite and hornblende and a lot of others. In the field you probably wouldn’t be able to tell the difference between a gabbro and a diabase. A diabase is a variety of gabbro so they look much alike. One of the distinguishing minerals in diabase is LABRADORITE. If a crystal is large enough you’ll see flashes of color when you turn the specimen correctly; you’ll see mostly blues. Lot’s of times you’ll see diabase used as architectural stone and for decorations and gravestones because they are harder and tougher than regular gabbro. Hope this helped.
