Precious gemstones are ones which are rarely available / costlier, semi-precious gemstones are the ones which are little easily available whose price are less costlier.
We all know that all the elements on universe are made in combination of some chemicals / minerals which is an scientific approach. And you can find the similar chemical composition in most of the gems as per my knowledge.
Can these gems be weared for astrological purpose will they do any mystical powers? Science doesn’t has this information. And for this information we have to refer our ancients sages like Varahamihira, Vaisampayana, Jaimini and others who have written with their sixth sense about the planets and its significators on earth even before the launch of telescope and for which we have strong evidence.
GOD BLESS!!!
Srinivasa Temkar