igneous
Diabase
Diabase (Dolerite)
AI-generated identification · may be incorrectHardness of 6-7 on Mohs scale, dark gray to black color, submetallic to dull luster, composed mainly of plagioclase feldspar and pyroxene with a diabasic texture.
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Physical properties
Hardness of 6-7 on Mohs scale, dark gray to black color, submetallic to dull luster, composed mainly of plagioclase feldspar and pyroxene with a diabasic texture.
Formation & geological history
Formed from cooling mafic magma intruded into shallow crustal chambers as dikes or sills, typically during tectonic rifting events.
Uses & applications
Used extensively as crushed stone for construction, aggregate in concrete, and dimension stone for monuments and roadbeds.
Geological facts
Diabase is chemically identical to basalt and gabbro but differs in crystal grain size and cooling rate; it frequently forms impressive columnar jointing.
Field identification & locations
Identify in the field by its dark, fine-to-medium-grained crystalline appearance with visible interlocking plagioclase laths; found globally in ancient and modern intrusive formations.
