Natural Iolite Crystals

Natural iolite raw crystals.  Iolite is such an interesting mineral because it's trichroic.  The same crystal can look blue, grey, or yellow depending on orientation of the crystal.  Fascinating, as Mr. Spock would have said.

5 pieces with a total weight of 29 grams.  No treatment.

Note: one photo is backlit to show colors.