Solis gemma[1] is white, and, like the luminary from which it takes its name, emits brilliant rays in a circular form. Sagda is found by the people of Chaldæa adhering to ships, and is of a leek-green colour. The Isle of Samothrace gives its name to a stone[2] which it produces, black and imponderous, and similar to wood in appearance. Sauritis[3] is found, they say, in the belly of the green lizard, cut asunder with a reed. Sarcitis[4] is a stone, like beef in appearance. Selenitis[5] is white and transparent, with a reflected colour like that of honey. It has a figure within it like that of the moon, and reflects the face of that luminary, if what we are told is true, according to its phases, day by day, whether on the wane or whether on the increase: this stone is a native of Arabia, it is thought. Sideritis[6] is a stone like iron, the presence of which in lawsuits creates discord. Sideropœcilos,[7] which is a variety of the same stone, is a native of Æthiopia, and is covered with variegated spots.

Spongitis has its name from its resemblance to sponge. Synodontitis is a stone found in the brain of the fish known as "synodus."[8] Syrtitis is a stone that used formerly to be found on the shores of the Syrtes,[9] though now it is found on the coasts of Lucania as well: it is of a honey colour, with a reflected tint of saffron, and contains stars of a feeble lustre within. Syringitis[10] is hollow throughout, like the space between the two joints in a straw.