Looking for Quality Gems.

I am looking for any angle to make some extra money.  Prospecting, dectecting, cache hunting, thinking about writing and even trying to get some lead from rifle bullets to recycle.  I had a bad experience with the last one.  Anyway now I am looking into looking for diamonds and gems.  I have heard they may be plentiful in Colorado and Wyoming and they were even mining them for a few years in Colorado.  So I have been looking at maps and figuring a strategy.  I realize that it won't be easy as it's like looking for a needle in a haystack and you may have to go through tons of rock to find one diamond and then it may not be gen quality.  So I will settle for any gem of good quality.  In fact I may focus on garnets among others.  Garnets are seemingly plentiful and possible to get some good quality ones for gems.  So I am looking all over now for diamonds and gems and will use several strategies to do so.  If I just had a vehicle to get to where I can look I believe I can be successful.