This is the third time, out of the last 4 or 5 times, I've mined this garnet deposit in the Cordor coal mines, and gotten nothing. Once or twice I've mined it and gotten like 1 gem. I get more gems from tourmaline, onyx, sapphire, etc., deposits - this is literally the only kind of gem this happens with, and I'm both using a tool and have the Loremaster gathering secret, so this really shouldn't be happening so frequently (if at all), I assume.