Mention is made in the Old Testament of two kinds of purple, or purple dye: (1) "argaman" (Aramaic, "argevan"; Greek, πόρφυρα), probably the bright-red purple, which was costliest when it had the color of coagulated blood, and appeared black when viewed directly, but lustrous red when viewed obliquely; (2) "tekelet" (Greek, ὑάκινϑος), which, according to Philo and Josephus, resembled the color of the sea, the air, or the clear sky, and was, therefore, termed also blue. In instances it was black or dark-colored.
It is now possible to ascertain from what source the ancients obtained their purple dye. There are remains of the old workshops for making purple at Tarentum, in the Morea, and especially at Tyre. These consist of concrete hill-shaped masses of spiral-like shells. An examination of these heaps has up to the present revealed only two kinds of murex, found on the Mediterranean coast, Murex brandaris and Murex trunculus; the former at Tarentum and in the Morea, and the latter at Tyre. Without doubt, of the two kinds of murex described by Pliny, the one which he calls "purpura" or "pelagia" is not the species now so called, but Murex brandaris, as he mentions not only the spines on the whorl of the shell, but also the duct which is a prolongation of the aperture. This duct he thought contained the tongue, though, as a matter of fact, it holds the respiratory organ of the mollusk. Probably he included Murex trunculus under the same name.
Besides these two, another species of the present genus Purpura is found in the Mediterranean, Purpura hœmastoma, the purple juice of which is even now occasionally used by the inhabitants of the coast for marking linen. Although shells of these mollusks have not yet been found among the remains of ancient purple dye-works, it is likely that the ancients knew and used them, as they answer better than Murex trunculus to Pliny's description of the second species mentioned by him, Murex buccinum.
The pigment is secreted by a gland in the lining of the stomach. The juice is at first whitish, but changes on exposure to the atmosphere, and becomes successively yellowish and greenish, and atlast either reddish (in the species Murex brandaris and Purpura hœmastoma) or violet (in Murex trunculus). The moliusks were found on the Phenician coast, on the Palestinian shores, farther south (as at Dor), on the coast of Caria in Asia Minor, on the Laconian coast of Greece, on the shores of the strait of Euripus, and on the North-African coast. It is remarkable that in the Old Testament mention is made of purple imported into Tyre, but not of that made in Phenicia itself, although the Phenicians were regarded by the ancients as the discoverers of purple-dyeing, and the manufacture of purple was known to them in very early times.
Purple fabrics were very costly. Both kinds of purple were used for the carpets and curtains of the tabernacle, and for the high priest's gala dress, as also for the curtain of the Holy of Holies in the Temple. Bluish purple was used more extensively for sacred purposes than reddish. Blue material was used for the entire outer garment of the high priest as well as for the covers put over the sacred chattels in transportation. Red was used only in the cloth of the altar of burnt offerings. The loops holding the curtains of byssus in the tabernacle (Ex. xxxvi. 11), the "lace" fastening the high priest's breast-plate and miter (ib. xxviii. 28, 31, 37, 39), and the threads of the tassels on every Israelite's outer garment had to be made of bluish purple.
No mention is made of purple garments of Israelitish kings, with the exception of the reddish-purple seat (covering?) of Solomon's chariot (Cant. iii. 10), whereas references occur to the reddish-purple raiment of the kings of Media (Judges viii. 26), and the blue raiment of Assyrian "captains and rulers" (Ezek. xiii. 6). At the Babylonian court the bestowal of reddish-purple raiment was a mark of the highest favor (Dan. v. 7, 16, 29; comp. I Macc. x. 20, 62, 64; xi. 58; xiv. 43 et seq.; II Macc. iv. 38).