Geology - Crystal formation

 https://www.britannica.com/science/crystal

https://geology.com/minerals/crystal-habit/

https://www.ducksters.com/science/crystals.php

https://thecitrinecircle.com/blogs/crystals-in-depth-1/what-crystals-you-can-find-in-the-uk

https://sciencing.com/crystals-5640076.html