Gem, Rock, and Mineral Postage Stamps Featuring
Diabase

Rock Name:	Diabase
Composition:	A basaltic rock composed chiefly of labradorite and pyroxene, in which lath-shaped crystals occur.
Industrial Uses:	Ornamental stone; crushed stone.
Additional Notes:	In the United States, diabase is also referred to as dolerite. In the United Kingdom, dolerite is used to describe the fresh rock; diabase is used to refer to altered dolerite. Commonly occurs as tabular masses that have been intruded into surrounding rocks. The Palisades of the Hudson River, near New York City, are composed of diabase.


Diabase (Doleritic Basalt) Afars & Issas Scott 349 10 francs 22 Nov 1971	Olivine Diabase (Olivine Dolerite) Afars & Issas Scott 352 40 francs 25 Jan 1971

Scott 349 and 352 show thin-sections of rocks viewed under polarized light.