Show OF PEACOCK 04 S STONE DELAYS ARCH work on war memorial Is postponed for a year Wasl washington ilD ton theft of a sample mock of the mineral to be used in the base of the rainbow division arch in new york city way may delay work on this war memorial for a year according to the sculptor rills particular sample block was needed in matching materials for the memorial the finest specimens of beautifully iridescent member of tile the feldspar family come from certain sections of the labrador coast which are icebound ice fee bound much of the year says a bulletin from the national geographic society this peacock stone is found also in fit norway and in siberia but it was cr fit crt t idem hied as it a distinct species from rock samples picked up on pauls island on tile the north labrador coast in 1770 and named for the region of its discovery stone itself itsel somber gray although is noted among mineralogists for or its brilliant sheen and flashing blue purple green bronze bronze and red light rays of exquisite beauty Jie auty the mineral itself possesses no polor olor other than a somber gray 1 the play of many glossy lines hues glen gion off by the stone in sunlight is the result of optical interference in other words the intern internal al structure of the mineral breaks up into its color components the alie white light which penetrates the 0 lassy glassy sur f face ace some of these t rays are absorbed by the stone and do not affect the eye the rest are reflected its as brilliantly colored lashes flashes by thousands ands upon thousands of microscopic 1 particles within the feldspar a r t in the mineralogy wing of the nas jt ional museum in fit washington a large piece bece of 1 abrado rite is so pl placed aced in a i glass case that its cut and polished polis lied face catches tile the eyes of visitors visitor as soon as they enter the wing 7 although athe case stands well back toward the alie middle iddle a of a long hall this specimen has has a bluish green sheen somewhat alike tike that of the wings 0 of tropical butterflies ter flies used to decorate trays and pictures tures step a few feet to the right pr or left of the polished face of the stone however lio wever and it becomes an inert gray mass resembling a piece of kr granite anite I 1 quarry a dazzling spot blue green is the commonest coloration given off by the mineral but amany many specimens have been found a bronze red hue lovely to behold from others yellow violet arri ard orange 1 tints lash flash like the lame flame of a fire opal out but of the iridescent crystals the chief source of this mineral s a lonely region along the Labra labrador dr coast north of hamilton inlet A few years bears ago an enterprising american t opened a quarry on the island of near nain about between tile the northern tip of labrador ta labrador brador and hamilton inlet and attempted f to place on the 6 market arket as a semiprecious semi precious stone the enterprise apparently was not successful cess ful but the abandoned quarry Is lit a dazzling spot in the sunlight with i ahe rou rough h faces of the rock throwing off gorgeously tinted rays that lash flash and change with every new an angle gle of vision pieces of have been set lin n jen jewelry elry although the stone is didi cult r to work aits its cleavable nature band brittleness usually prevent the i jc cutting utting of a well polished surface for the same reason its use is lim jim cited tn in building construction although it is sometimes employed as a decorative feature skilled stone cutters have made vases and lamp bases from that are particularly prized by art collectors the mineral owes its or origin in to volcanic action in the labrador region millions of years ago molten rock forced between layers of older rock crystallized and formed deposits of and other minerals which were later exposed by erosion |