Practice Test Geeks(GIA) Certified Diamonds Gemological Institute of America Practice Test
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Diamond Grading and Identification Flashcards

7 cards from real GIA practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.

Read the first 7 Diamond Grading and Identification flashcards as text

  1. Which instrument is primarily used to separate a natural diamond from a cubic zirconia based on thermal conductivity?

    Answer: Diamond thermal tester (probe)

    A diamond thermal tester measures thermal conductivity, which is exceptionally high in diamond compared to simulants like cubic zirconia.

  2. What is the refractive index of diamond?

    Answer: 2.417

    Diamond has a refractive index of 2.417, one of the highest of any natural gemstone.

  3. A 'knot' inclusion is best described as:

    Answer: A diamond crystal that reaches the surface of the finished stone

    A knot is an included diamond crystal that extends to or breaks the surface of the polished stone.

  4. Which GIA cut grade is the highest achievable for a standard round brilliant diamond?

    Answer: Excellent

    GIA's highest cut grade is 'Excellent,' which represents the top tier of cut quality for standard round brilliant diamonds.

  5. In GIA terminology, what is the 'culet'?

    Answer: The small facet or point at the very bottom of the diamond pavilion

    The culet is the small flat facet (or pointed tip) at the very bottom of the pavilion.

  6. What is the specific gravity (density) of diamond?

    Answer: 3.52

    Diamond has a specific gravity of approximately 3.52, which is relatively low compared to many other gemstones.

  7. A GIA Diamond Grading Report for a fancy-shaped diamond does NOT include which element that is present on a Round Brilliant report?

    Answer: An overall cut grade

    GIA issues an overall cut grade only for standard round brilliant diamonds; fancy shapes receive polish and symmetry grades but no overall cut grade.

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