Geodes are often lined with quartz.
Quartz
hard strong rocks
Intrusive igneous rocks, (Plutonic rocks)
A hollow rock with crystals might be called a geode. A geode is a type of sedimentary rock that has crystals formed inside due to volcanic heating and cooling or by other chemicals seeping into the rock.
technically, quartz is not a rock. it is a mineral. quartz can be found in any type of rock
A metamorphic rock
Quartz is a mineral, not a rock.
It's a type of quartz rock, only it's blue.
yes, it is. amethyst is a purple type of quartz.
the rock that is clear, is well it depends because there is more than 1 clear rock there is the diamond and a few others that you can see through and they are really crystals! it could be quartz..
quartz is a basic mineral and can be in any type of rock
A metamorphic rock