Emerald Gems Stone Gents Ring Jewellery Collection 41

 Emerald Gems Stone Gents Ring. 

a Fashion jewellery emerald gems stone gents ring mens-nautral-emerald-gemstone-ring-solid-18k-gold-and silwer rings collection

 By Aamir Mannan.

8.-2 DOUBLE REFRACTION AND DISPERSION

Thus is must be realised that if, say, a zircon is cut with is table facet at right-angles to optic axis it may be necessary to tile the stone and make observations trough the bezel facets to see the double refraction well developed. also, as R. T. liddicoat has pointed out, in directions at right-angle to the optic 

axis of the uniaxial minerals, although the double refraction is at is greatest is cannot be directly observed, as the image due to the extraordinary ray is either directly in front or directly behind that the due to the ordinary ray. with zircon, sphene, and peridot the birefringence  is so strong that even the novice should have no difficultly in seeing the effect mentioned effect in quartz and corundum 

unless the stone are larger. (J.-P. Poirot, director of the paris gem-testing laboratory, has made the important observation that  for a given birefringence the doubling effects is more marked in stones of low R.I. than in those of high index.)

8.-2 DOUBLE REFRACTION AND DISPERSION
Thus is must be realised that if, say, a zircon is cut with is table facet at right-angles to optic axis it may be necessary to tile the stone and make observations trough the bezel facets to see the double refraction well developed. also, as R. T. liddicoat has pointed out, in directions at right-angle to the optic axis of the uniaxial minerals, although the double refraction is at is greatest is cannot be directly observed, as the image due to the extraordinary ray is either directly in front or directly behind that the due to the ordinary ray. with zircon, sphene, and peridot the birefringence  is so strong that even the novice should have no difficultly in seeing the effect mentioned effect in quartz and corundum unless the stone are larger. (J.-P. Poirot, director of the paris gem-testing laboratory, has made the important observation that  for a given birefringence the doubling effects is more marked in stones of low R.I. than in those of high index.)