DEMANTOID

demantoid, the name given by nils gustaf nordenskiold to a green garnet, found in the urals and used as a gem stone. as it possesses high refractive and dispersive power, it presents when properly cut great brilliancy and "fire," and the name has reference to its diamond-like appearance. it is sometimes known as "uralian emerald," a rather unfortunate name inasmuch as true emerald is found in the urals, whilst it not infrequently passes in trade as olivine. demantoid is regarded as a lime-iron garnet, coloured probably by a small proportion of chromium. the colour varies in different specimens from a vivid green to a dull yellowish-green, or even to a brown. the specific gravity of an emerald-green demantoid was found to be 3.849, and that of a greenish-yellow specimen 3.854 (a. h. church). the hardness is only 6.5, or lower even than that of quartz--a character rather adverse to the use of demantoid as a gem. this mineral was originally discovered as pebbles in the gold-washings at nizhne tagilsk in the ural mountains, and was afterwards found in the stream called bobrovka, in the sysertsk district on the western slope of the urals. it occurs not only as pebbles but in the form of granular nodules in a serpentine rock, and occasionally, though very rarely, shows traces of crystal faces. (f. w. r.*) demaratus (doric [greek: damaratos], ionic [greek: demaretos]), king of sparta of the eurypontid line, successor of his father ariston. he is known chiefly for his opposition to his colleague cleomenes i. (q.v.) in his attempts to make isagoras tyrant in athens and afterwards to punish aegina for medizing. he did his utmost to bring cleomenes into disfavour at home. thereupon cleomenes urged leotychides, a relative and personal enemy of demaratus, to claim the throne on the ground that the latter was not really the son of ariston but of agetus, his mother's first husband. the delphic oracle, under the influence of cleomenes' bribes, pronounced in favour of leotychides, who became king (491 b.c.). soon afterwards demaratus fled to darius, who gave him the cities of pergamum, teuthrania and halisarna, where his descendants were still ruling at the beginning of the 4th century (xen. _anabasis_, ii. 1. 3, vii. 8. 17; _hellenica_, iii. 1. 6); to these gambreum should perhaps be added (athenaeus i. 29 f). he accompanied xerxes on his expedition to greece, but the stories told of the warning and advice which on several occasions he addressed to the king are scarcely historical. see herodotus v. 75, vi. 50-70, vii.; later writers either reproduce or embellish his narrative (pausanias iii. 4, 3-5, 7, 7-8; diodorus xi. 6; polyaenus ii. 20; seneca, _de beneficiis_, vi. 31, 4-12). the story that he took part in the attack on argos which was repulsed by telesilla, the poetess, and the argive women, can hardly be true (plutarch, _mul. virt._ 4; polyaenus, _strat._ viii. 33; g. busolt, _griechische geschichte_, ii.^2 563, note 4). (m. n. t.)