Occurrence:
Worldwide. A member of
the chalcedony family (micro-crystalline quartz).
Appearance:
Bands of sard (brownish
red) and onyx (white), occasionally with agate (translucent).
Something Extra:
Sardonyx brings good
luck if set in gold and engraved with an eagle. It is a parallel-layered
agate having brown color as one of its layers. It has two to five layers
alternately stacked with dark and light tones. These stones are not easily
found and most are dyed.
Sardonyx was highly valued in Rome, especially for seals, because it was said to never stick to the wax. Roman General Publius Cornelius Scipio was known for wearing lots of sardonyx.