Oica is the barbarian name given to a stone which is pleasing for its colours, black, reddish yellow, green, and white. Ombria,[1] by some called notia,"[2] falls with showers and lightning, much in the same manner as ceraunia[3] and brontea,[4] the properties of which it is said to possess. There is a statement also, that if this stone is placed upon altars it will prevent the offerings from being consumed. Onocardia[5] is like kermesberry in appearance, but nothing further is said about it. Oritis,[6] by some called "sideritis,"[7] is a stone of globular form, and proof against the action of fire. Ostracias,[8] or ostracitis, is a testaceous stone, harder than ceramitis,[9] and similar in all respects to achates,[10] except that the latter has an unctuous appearance when polished: indeed, so remarkably hard is ostritis, that with fragments of it other gems are engraved. Ostritis[11] receives its name from its resemblance to an oyster-shell. Ophicardelon is the barbarian name for a stone of a black colour, terminated by a white line on either side. Of Obsian[12] stone we have already spoken in the preceding Book. There are gems, too, of the same name and colour, found not only in Æthiopia and India, but in Samnium as well, and, in the opinion of some, upon the Spanish shores that lie towards the Ocean.