May 1997 Gem Quiz

1. Refractometer testing for the optic sign of the gemstone synthetic rutile may yield uniaxial positive results?
   False
   True

2. The yellow, transparent gemstone olivine can exhibit both splintery fracture characteristics and vitreous luster?
   False
   True

3. The definition: "a cut usually more elongated the briolette with a circular cross section and facets of differing sizes and shapes arranged in rows and decreasing in the number of facets per row as they approach the points" applys to standard round brilliant?
   True
   False

4. Refractometer testing for the optic sign of the gemstone cordierite may yield biaxial results?
   True
   False

5. Strontium Titanate is found commonly in a semi-transparent form?
   False
   True

6. Orthoclase is said to have strong dispersion?
   True
   False

7. Malachite commonly can exhibit vitreous luster?
   True
   False

8. Red/pink is a color associated with the short wave ultraviolet excitation of the gemstone synthetic corundum flux?
   True
   False

9. Orient is a phenomena associated with the gemstone obsidian?
   True
   False

10. The definition: "a proprietary name for a modification of the brilliant cut, expanding 8 fold symmetry to ten fold, having 10 star, 20 bezel, 30 upper girdle, a table, 30 lower girdle, 10 pavilion and a culet facet" applys to kite cut?
    True
    False

11. A refractometer, when used properly with a monochromatic sodium light source, may yield a refractive index value for the isotropic gemstone plastic of 1.642?
    True
    False

12. The specific gravity of rhodonite can fall within the range of 3.37 to 3.82 grams per cubic centimeter?
    True
    False

13. Andalusite can show a strong trichroic pleochroic response when carefully tested with a dichroscope?
    True
    False

14. The refractometer, when used properly with a monochromatic sodium light source, may yield a birefringence value for jet of 0.003?
    False
    True

15. The specific gravity of andradite can fall within the range of 3.81 to 3.85 grams per cubic centimeter?
    False
    True

16. The definition: "squarish brilliant cut with rounded corners, sometimes refered to as an old mine cut" applys to half-moon brilliant cut?
    True
    False

17. The Moh's hardness of beryl is approximately 8.6?
    True
    False

18. The polariscope may yield doubly refractive or aggregate results when testing the gemstone spinel?
    True
    False

19. Brown/tan is a color associated with the long wave ultraviolet excitation of the gemstone quartz?
    True
    False

20. Refractometer testing for the optic sign of the gemstone yag may yield biaxial positive results?
    True
    False

GemData will continue to have a future Gem Quiz each month. Would you like to see your questions used for a future Gem Quiz? GemData will be happy to post the persons name who submitted the question if so desired. Please submit your questions on any subject to do with the Gem, Diamond or Jewelry Industry with the answers to Lance Kanaby at lkanaby@buffnet.net