noun
spar
A crystalline mineral that splits readily along flat surfaces.
The spar splits cleanly along flat surfaces when gently struck.
Etymology
The Germanic mineral-name refers to material that readily separates into pieces. English retained it in names for cleavable crystalline minerals.
More examples
- The geologist identifies the pale spar as calcite.
- Clear Iceland spar produces a double image of printed letters.
- A vein of white spar runs through the rock.
Forms
spar · spars