Which way do you use your Rose Quartz Crystal were relationships and friendships are concerned?
a short answer 1. sandstones are not 100% quartz and the impurities can get removed in the metamorphic process 2. quartz undergoes a strange process called pressure solution whereby under stress the grain contacts dissolve against each other and re-fuze making almost like a weld between the individual grains. This can be seen under thin section
In a quartzite, impurities are recrystallised to new mineral species and quartz develops sutured grain boundaries which are interlocking and very strong.
