This is a very rare example of that color-shifting plagioclase feldspar known more commonly as "moonstone" for its pearlescent shimmer and play of colors. This small find came out of one pocket, found in the late 1980s. I remember seeing them at what I thought were insane prices at the time, quite clearly. Today, they are impossible to obtain and remain one of the best natural illustrations of this interesting varietal of feldspar. This is as good a piece as I think exists for sale, and is better than any I remember seeing at the time. In person, it is MUCH better, too! It is very 3-dimensional, very "sillky," and has good play of colors in shifting light.