Last seen in:
- Eugene Sheffer - King Feature Syndicate - Sep 20 2024
- L.A. Times Daily - Aug 20 2023
- The Washington Post - May 29 2019
- L.A. Times Daily - May 29 2019
- Eugene Sheffer - King Feature Syndicate - May 9 2017
- L.A. Times Daily - Apr 21 2016
- L.A. Times Daily - Sep 6 2015
- L.A. Times Daily - Oct 28 2014
- Eugene Sheffer - King Feature Syndicate - Oct 17 2014
- USA Today - Jun 15 2014
Related Clues:
- Mineral that can be cleaved
- Flakes in geology class
- Muscovite, e.g
- Source of gas market includes hydrogen
- Type of rock formed from igneous or sedimentary rocks
- Fracking target
- Mineral in thin layers
- Mineral used in insulation
- Fuel oil source
- Thin, flaky mineral
- Mineral in insulation
- Rock that's fracked
- Fossil-yielding sedimentary rock
- Flexible mineral found in igneous and metamorphic rocks
- Crumbly silicate