January 1997 Gem Quiz

1. Which of the orange, semi-transparent gemstones listed below can exhibit the uneven fracture characteristics and vitreous luster of the gemstone oligoclase?
   Jadeite
   Beryl
   Synthetic Corundum Verneuil
   Zircon

2. Even fracture characteristics can be exhibited by which of the following gemstones?
   Andalusite
   Synthetic Emerald Hydrothermal
   All of these
   Hematite

3. Which of the blue, transparent gemstones listed below can exhibit the conchoidal fracture characteristics and adamantine luster of the gemstone synthetic corundum flux?
   Strontium Titanate
   Cubic Zirconia
   Spinel
   None of the above

4. When carefully tested with a dichroscope the monoclinic gemstone spodumene can show which of the following responses?
   There is no single best choice
   Weak trichroic
   Strong trichroic
   Moderate dichroic

5. A refractometer, when us ed properly with a monochromatic sodium light source, may yield a refractive index value for the triclinic, biaxial gemstone microcline of?
   1.523
   1.521
   All of these
   1.537

6. The Moh's hardness of tortoise shell can be?
   3.200
   None of these
   3.800
   2.700

7. Quartz commonly can exhibit which of the following fracture characteristics?
   Uneven
   Splintery
   All except # 4
   Step-like

8. The refractometer, when used properly with a monochromatic sodium light source, may yield a birefringence value for grossularite of?
   0.010
   0.009
   None of these
   0.024

9. Labradorite is known to exhibit which of the following phenomenas?
   Chatoyancy
   Adularescence
   Girasol
   None of these

10. When carefully tested with a dichroscope the orthorhombic gemstone zoisite can show which of the following responses?
    Weak trichroic
    There is no single best answer
    Moderate dichroic
    Weak trichroic

11. The specific gravity of flourite is?
    3.190
    3.370
    2.850
    2.930

12. Which of the red, opaque gemstones listed below can exhibit the splintery fracture characteristics and dull luster of the gemstone calcareous coral?
    Hydrogrossular
    Shell
    None of these
    Rhodonite

13. Which of the gray, semi-transluscent gemstones listed below can exhibit the even fracture characteristics and dull luster of the gemstone orthoclase?
    Plastci
    Jadeite
    Obsidian
    Calcite

14. Corundum commonly can exhibit which of the following fracture characteristics?
    Granular
    Even
    There is no single best choice
    Splintery

15. When carefully tested with a dichroscope the triclinic gemstone rhodonite can show which of the following responses?
    Moderate dichroic
    Moderate trichroic
    Weak dichroic

16. Zoisite is known to exhibit which of the following streak plate responses?
    Reddish brown
    Colorless
    Purple red
    Grayish black

17. Su adamantine luster is exhibited by which of the following gemstones?
    Amber
    Andradite
    Rhodocrosite
    Conchiolin coral

18. Which of the red, transluscent gemstones listed below can exhibit the granular fracture characteristics and dull luster of the gemstone rhodocrosite?
    Calcite
    There is no single best answer
    Amber
    Nephrite

19. Corundum can commonly exhibit which of the following fracture characteristics?
    Granular
    Splintery
    All of these
    Uneven

20. Which of the following gemstones cannot be commonly found in the semi-transluscent form?
    Glass
    Chalcedony
    Spinel
    Topaz

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