June 1997 Gem Quiz

1. The refractometer, when used properly with a monochromatic sodium light source, may yield a birefringence value for opal of 0.024?
   True
   False

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

3. The refractometer, when used properly with a monochromatic sodium light source, may yield a birefringence value for topaz of 0.009?
   False
   True

4. Brown/Tan is a color associated with the long wave ultraviolet excitation of the gemstone chalcedony?
   False
   True

5. Orient is a phenomena associated with the gemstone chrysoberyl?
   False
   True

6. The polariscope may yield aggregate results when testing the gemstone beryl?
   False
   True

7. Synthetic rutile is said to have moderate dispersion?
   False
   True

8. Andalusite has a scarlet red streak plate test response?
   False
   True

9. Pyrope is found commonly in an opaque form?
   False
   True

10. Andalusite is said to have very strong dispersion?
    True
    False

11. The refractometer, when used properly with a monochromatic sodium light source, may yield a birefringence value for synthetic corundum flux of 0.009?
    False
    True

12. Refractometer testing for the optic sign of the Cubic gemstone spinel may yield uniaxial results?
    False
    True

13. Cubic Zirconia is found commonly in an opaque form?
    True
    False

14. Moldavite commonly can exhibit either splintery and/or step-like fracture characteristics?
    False
    True

15. The Moh's hardness of turquoise is approximately 5.9?
    False
    True

16. The gemstone jadeite (GIA) exhibits a characteristic weal band at 433 nanometers?
    False
    True

17. The gemstone synthetic emerald flux exhibits a characteristric strong band at 427 nanometers?
    False
    True

18. The gemstone synthetic rutile exhibits a characteristric weak doublet at 425 nanometers?
    False
    True

19. Synthetic Emerald Hydrothermal can show a moderate trichroic pleochroic response when carefully tested with a dichroscope?
    False
    True

20. The gemstone synthetic emerald flux exhibits a characteristic weak line group at 427 nanometers?
    False
    True

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