Large Sardonyx Pebbles

A Sardonyx stone is a variation of onyx, which is a semiprecious stone of the silica mineral agate comprised of the chemical make-up SiO2. Onyx stones have the same properties as quartz stones. Sardonyx features many layers of quartz fibers stacked on top of one another that form translucent, opaque and solid banded colors over time.

Sardonyx stones, also called banded agate, are onyx variations that feature distinctive red and brown bands of color in contrast to the sleek, pure black stones that are perhaps the most famous of these semiprecious gems. Sardonyx stones are easily identified by their alternating dark and light bands of flat white, gray, red and brown colors.