Eagle Eye Gemstone Beads

Eagle Eye Semiprecious Gemstone Beads: It's difficult to find reliable information on Eagle Eye. We've been told it's jasper, but it has hints of translucence that don't normally occur in jaspers. Is it feldspar (like moonstone and labradorite)? Is it a gray form of tigereye? Is it Hawk's Eye (the name for an earlier form of tigereye)?

Whatever it is, our current batch of Eagle Eye beads are striped like tigereye, and these stripes of light and dark gray have a subtle shimmer or chatoyancy. Many of the stripes are parallel, and some are swirled. It almost certainly is a variety of quartz. If it is simply gray tigereye, then we know that the stripes are oriented fibers of crocidolite (a mineral of the amphibole group) that have been replaced by silica. And it's lacking the iron that commonly gives tigereye its warm hues.