There are 12 signs (Rashis), 9 planets and 27 constellations in Hindu astrology. And, now a days astrologers around the world use gems as a remedy freely. Gems are being used as a remedy since very long around the world. There is no mention of any gemstone in BPHS, but some classics could have some explanation that I don’t know.
Cheiro had advocated gems very freely. How many and which one he wore, we will never know, but in last times he had lost all his predictive abilities because of his pendant was lost which he had acquired from India. At present, almost every astrologer recommends gems for betterment of the native.
Whatever it could be, but past is past. I have tried gems on clients and they do show effects, which is a fact for me, as I have experienced on myself and on my clients. Every planet is allotted a gem stone –