So hard to choose! Prehnite, fluorite, malachite, and euclase have prominent positions on my desk right now, but I rotate the line-up every now and then. The one that's been up the longest is a botryoidal cluster of prehnite with epidote crystals, which looks good enough to eat! I turn it around and put it in different positions, every angle radiates a pure fresh spring-green aura from the round prehnite wrapping around the hard-edged, straight-lined energy of the black epidote.
Yeah, I think the prehnite is the one with staying power, the one I just can't put in a cabinet or a drawer. It is my favorite individual crystal (well, crystals really). My favorite *type* of stone...oh, that'd take another rambling paragraph to answer! But perhaps I'll browse my collection, enjoy the radiance and shininess, and see what speaks to me...