The late Scott Cunningham has a good book on gems. It is really geared towards making a gem-based tarot, unlike the James Wanless Voyager tarot or the gemstone tarot where there are pictures of gems, here you literally use 78 gems to put your deck together and put them together in a reading. Pity this cannot be done with herbs.
We know someone who did that and loves it. Most of Cunningham’s picks are inexpensive so it is possible for under $75.00, which is not that bad considering some art decks go for upwards of $100.00 and mass produced one are around $30.00.
If you are interested, pick up a copy and indulge your gem obsession. Here’s a page from his book on the ruby.