bluestone

1. (countable, uncountable)Any of several bluish-grey varieties of stone used for construction

   bluish-grey sandstone used for paving and building

2. Any of several bluish-grey varieties of stone used for construction:

   (UK, countable, uncountable)A form of dolerite which appears blue when wet or freshly broken.

3. (UK, countable, uncountable)Any of the several (massive) kinds of non-local stone (particularly dolerite) used to construct Stonehenge.

4. (Canada, US, countable, uncountable)A feldspathic sandstone found in the US and Canada.

5. (US, countable, uncountable)A form of limestone found in the Shenandoah Valley and some other places.

6. (Australia, New Zealand, countable, uncountable)A bluish-grey basalt or olivine basalt.

7. (Australia, South, countable, uncountable)Slate, such as comes from quarries in or near Adelaide.

8. Either of two related copper- and sulfur-based bright blue stones:

   (countable, uncountable)Copper(II) sulfate, CuSO₄(H₂O)ₓ where x is 0-5, used as a coloring agent in glass-making and pottery and for other purposes.

9. (countable, uncountable)Chalcanthite, a water-soluble sulfate mineral, CuSO₄·5H₂O.

10. (countable, uncountable)Lapis lazuli, or its core constituent, lazurite.

regular