How are quartz formed.are they valuable?
Interesting rock. Other than the quartz, which is visible in the first image, a geologist would need to see the specimen to look at it with a hand lens to determine if there are other minerals present. It appears to be a breccia, which is usually associated with a fault. I suggest taking your rock to a local geologist to help with further identification. As for the last question, diamonds are the hardest minerals (10), emerald (also known as beryl) has a hardness of 7.5 - on the Mohs hardness scale. Quartz is 7. https://en.wikipedia.org/wiki/Mohs_scale_of_mineral_hardness
There are other characteristics to use to identify the differences between the minerals. A Rock and Minerals Identification book is a good reference to have on hand. Good luck with your rock!