sardoine

CONT: La sardoine fait partie de la grande famille des quartz et désigne un quartz polycristallin translucide à grains fins de couleur beige à brun uniforme [...]

CONT: Sard is a translucent chalcedony that is brown to dark reddish-brown. It is formed from the deposition of silica at low temperatures from silica-rich waters percolating through cracks and fissures in other rocks.
OBS: ... similar to ""carnelian"" but having less intense colors (darker and more brownish), and classed by some as a variety of carnelian.