BRIGHTNESS OBSERVING INSTRUMENT FOR GEM SUCH AS DIAMOND AND PHOTOGRAPHING METHOD FOR GEM USING THE INSTRUMENT

摘要

PURPOSE:To enable even an amateur to decide the brightness of a gem by composing the instrument of a lower cylinder part which is made of an opaque material and has its internal bottom part as a gem mount part, an upper cylinder part provided on it, and a lens for magnified observation provided at the upper tip of the upper cylinder part. CONSTITUTION:The lower cylinder part 5 is so constituted that a cylinder main body (having a black, blackish, or red inner peripheral surface) is fitted to a base part 51 detachably through a step part 8. The top surface of the base part 51 constitutes the gem mount part 11 (having a black or blackish surface) and a recessed part 9 is formed in its center. The lower cylinder part 5 has such an internal diameter/height size ratio that the angle alpha between the line connecting its upper edge and the center of the mount part 11 and the axis of the lower cylinder part is 10 - 25 deg.. The upper cylinder part 6 is made of a white or milk-white translucent material (e.g. polyethylene resin) and fitted to the upper end of the lower cylinder part 5. Then a lens 7 held in a holding ring 10 is fitted to the upper end. Then a diamond is set in the recessed part 9 and observed through the lens 7, and consequently the pattern of the diamond corresponding excellently to its brightness can be observed.