In the Mandaean representation the sky is an ocean of water, pure and clear, but of more than adamantine solidity, upon which the stars and planets sail.
The lustre is resinous to adamantine, and the index of refraction high (2.369 for sodium light).
For this reason the mineral is not always readily recognized by inspection, though the perfect dodecahedral cleavage, the adamantine lustre, and the brown streak are characters which may be relied upon.
At Little Bytham a very hard brick, called adamantine clinker, is made of the siliceous clay that the Romans used for similar works.
Crystals of sulphur are transparent or translucent and highly refractive with strong birefringence; they have a resinous or slightly adamantine lustre, and present the characteristic sulphur-yellow colour.
Circumcision and Sabbath, separation from marriage with a foreigner, which rendered a Jew unclean, as well as strict conformity to the precepts of the Torah, constituted henceforth an adamantine bond which was to preserve the Jewish communities from disintegration.
With their resinous to adamantine lustre and their translucency they also present somewhat the appearance of horn; hence the name hornsilver.