Hilton Mine "yellows" are among the most coveted fluorites in the fluorite pantheon for obvious reasons! Nicely perched atop a stair step cluster of smaller fluorite crystals, this piece features a penetration-twinned fluorite crystal, 2.7 cm across, that is very lustrous and translucent. It exhibits a lemon yellow color. I am told that most of these came out in the 1960s to 1970s. In any case, they are few and far between, today. This gemmy, bright penetration twin is the best I have had in several years, from any old collections.