The shamir was made at twilight on the sixth day of creation together with other extraordinary things.[161] It is about as large as a barley corn, and it possesses the remarkable property of cutting the hardest of diamonds. For this reason it was used for the stones in the breastplate worn by the high priest. First the names of the twelve tribes were traced with ink on the stones to be set into the breastplate, then the shamir was passed over the lines, and thus they were graven. The wonderful circumstance was that the friction wore no particles from the stones. The shamir was also used for hewing into shape the stones from which the Temple was built, because the law prohibited iron tools to be used for the work in the Temple.[162] The shamir may not be put in an iron vessel for safe-keeping, nor in any metal vessel, it would burst such a receptacle asunder. It is kept wrapped up in a woollen cloth, and this in turn is placed in a lead basket filled with barley bran.[163] The shamir was guarded in Paradise until Solomon needed it. He sent the eagle thither to fetch the worm.[164] With the destruction of the Temple the shamir vanished.[165] A similar fate overtook the tahash, which had been created only that its skin might be used for the Tabernacle. Once the Tabernacle was completed, the tahash disappeared. It had a horn on its forehead, was gaily colored like the turkey-cock, and belonged to the class of clean animals.[166] Among the fishes there are also wonderful creatures, the sea-goats and the dolphins, not to mention leviathan. A sea-faring man once saw a sea-goat on whose horns the words were inscribed: "I am a little sea-animal, yet I traversed three hundred parasangs to offer myself as food to the leviathan."[167] The dolphins are half man and half fish; they even have sexual intercourse with human beings; therefore they are called also "sons of the sea," for in a sense they represent the human kind in the waters.[163]