Dark blue tiger's eye variety also known as Hawk’s Eye, polished round beads on a 15 inch strand. These stones are a natural dark blue to black color. Tiger's eye, normally a honey gold color, comes in different color varieties based on the mineral inclusions. If it is dark blue to grayish blue, it is called hawk's eye. Sometimes there are intermediate phases between the blue and the gold stones where they occur together. Enhancements and treatments also may be employed, such as acid washing the stones to remove all color, and heat treatments to change the stone’s color to red.
The light scattering and reflecting shimmer that is characteristic of this stone is called chatoyancy, and is caused by very thin silicate crystals formed into parallel arrangements resembling fine spun fiberglass. The substrate volcanic rock cooled and contracted to form narrow gaps or porous voids for the fibers to grow properly into the veins, often resulting in alternating layers of rock and crystal, resembling a ladder or stairway. Through additional geothermal and tectonic forces, more silica is percolated in between the layers of the earth gossamer threads to create a refractive lens over them. The hawk’s eye blue color comes from the iron inclusions that have not oxidized. Movement of the earth’s crust create waves in the crystal patterns such that they are reminiscent of silk or satin sheets.
Tiger's eye had been used as a warding stone against “evil eye”, and also as a talisman for frequent travelers and soldiers. Buddhist monks have been known to wear the beads as shambhala bracelets to assist in their meditation practice. Many people find the silky reflectance of a skillfully polished stone to be a source for inspiration.