Decemver 1996 Gem Quiz

1. Which of the black, opaque gemstones listed below can exhibit the conchoidal fracture characteristics and adamantine luster of the gemstone strontium titanite?
   Labradorite
   Synthetic Corundum Verneuil
   Opal
   Shell

2. Plastic is known to exhibit which of the following phenomenas?
   Adularescence
   Color change
   All of these
   Chatoyancy

3. Pyrope is known to exhibit which of the following streak plate responses?
   Grayish green
   White
   Brownish red
   Brick red

4. Almandine should always sink in which of the following specific gravity fluids?
   3.05
   3.32
   2.62
   All of the above

5. Adradite is found commonly in which of the following transparency classifications?
   Semi-transparent
   Opaque
   All of these
   Transluscent

6. The Moh's hardness of rhodonite can be?
   5.700
   There is no single best answer
   6.600
   5.500

7. The Moh's hardness of rhodocrosite can be?
   4.600
   4.700
   4.200
   3.200

8. Chrysoberyl should always float in which specific gravity fluids?
   3.05
   3.32
   None of these
   2.62

9. The refractometer, when used properly with a monochromatic sodium light source, may yield a birefringence value for calcareous coral of ?
   0.199
   0.196
   0.200
   0.198

10. Chrysoberyl is found commonly in which of the following tranparency classifications?
    Opaque
    All of these
    Transluscent
    Semi-transparent

11. The Moh's hardness of hydrogrossular can be?
    8.200
    7.800
    7.000
    7.900

12. Andalusite is known to exhibit which of the followinh phenomenas?
    Labradorescence
    Play of color
    None of these
    Color change

13. When carefully tested with a dichroscope the hexagonal gemstone synthetic emerald flux can show which of the following responses?
    Moderate trichroic
    Strong trichroic
    Weak trichroic
    Moderate dichroic

14. A refractometer, when used properly with a monochromatic sodium light source, may yield a refractive index value for the orthorhombic, biaxial gemstone pearl of?
    1.530
    1.259
    1.775
    2.101

15. Sodalite is known to exhibit which of the following streak plate responses?
    Grayish blue
    Colorless
    Pale green
    Grayish black

16. When carefully tested with a dichroscope the orthorhombic gemstone chrysoberyl can show which of the following responses?
    Weak dichroic
    All of these
    Moderate trichroic
    Moderate dichroic

17. The specific gravity of quartz is?
    2.690
    All of these
    2.640
    2.660

18. Synthetic Corundum Flux can show which of the following responses when carefully tested with a dichroscope?
    Moderate dichroic
    Moderate trichroic
    Weak trichroic
    Strong trichroic

19. The Moh's hardness of synthetic spinel verneuil can be?
    8.300
    8.400
    8.000
    8.100

20. Synthetic Corundum Verneuil commonly can exhibit which of the followinh lusters?
    Dull
    Pearly
    Vitreous
    Resinous

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