DIAMOND & DIAMOND GRADING EXAM
2025 WITH ANSWERS.
1. Crystal - correct answer -solid matter with atoms arranged in regular,
repeating pattern
2. Crystaline - correct answer -composed of crystals or related to crystals
3. Crystal planes - correct answer -internal directions parallel to a minerals
unit cell surfaces
4. Crystal shape - correct answer -geometric shape of a well formed
crystal
5. Crystal strucutre - correct answer -regular, repeating
arrangement of atoms in a mineral
6. Crystal systems - correct answer -categories of crystals based on their
symmetry and internal structure
,7. Doubling - correct answer -the appearance of double images of a gemstones
facet junctions on the side opposite the viewer
8. Doubly refractive - correct answer -(antisotropic)- possessing different
physical or optical properties in different crystal directions
9. Glassie - correct answer -a well shaped, transparent,
octahedral diamond crystal with sharp, square edges
10. Glide plane - correct answer -crystal distortion caused during growth
when one part of the lattice if offset in relation to the rest
11. Graining (grain lines) - correct answer -visible shadow like lines in a
diamond caused by irregularities in the crystal structure
12. Habit - correct answer -characteristic crystal shape of a specific
material
13. Macle - correct answer -a flat, triangular twinned diamond crystal
14. Singly refractive(isotropic) - correct answer -possessing the same
, physical or optical properties in all crystal directions
15. Specific gravity - correct answer -ratio of the weight of a material
to that of an equal volume of water
16. Tetrahedron - correct answer -in diamond, a group of five carbon
atoms with one at the center
17. Thermal conductivity - correct answer -the relative ability of a material
to transfer heat
18. Thermal expansion - correct answer -capcity of a material to expand
when its heated
19. Trace elements - correct answer -atoms in a gem that arent part of its
essential chemical composition
20. Twinned crystal - correct answer -crystal distorted during growth,
with two or more intergrown crystals with opposing crystal directions
21. Unit cell - correct answer -smallest group of atoms with the
, characteristic chemical composition and the basic crystal structure of a
mineral
22. The crystal places most suitable for cleaving a diamond are the... -
correct answer -octahedral planes
23. Squares or rectangles, trigons and parallel groves are types of... -
correct answer -growth marks
24. Which is the softest crystal direction in a diamond? - correct answer -
dodecahedral
25. Crystal shape is an important factor in the evaluation of rough
because... - correct answer -it affects the amount of weight retained
after cutting
26. The habit of a gem quality diamond is the... - correct answer
-octahedron
27. Another name for the cubic crystal system is... - correct answer -
isometric
2025 WITH ANSWERS.
1. Crystal - correct answer -solid matter with atoms arranged in regular,
repeating pattern
2. Crystaline - correct answer -composed of crystals or related to crystals
3. Crystal planes - correct answer -internal directions parallel to a minerals
unit cell surfaces
4. Crystal shape - correct answer -geometric shape of a well formed
crystal
5. Crystal strucutre - correct answer -regular, repeating
arrangement of atoms in a mineral
6. Crystal systems - correct answer -categories of crystals based on their
symmetry and internal structure
,7. Doubling - correct answer -the appearance of double images of a gemstones
facet junctions on the side opposite the viewer
8. Doubly refractive - correct answer -(antisotropic)- possessing different
physical or optical properties in different crystal directions
9. Glassie - correct answer -a well shaped, transparent,
octahedral diamond crystal with sharp, square edges
10. Glide plane - correct answer -crystal distortion caused during growth
when one part of the lattice if offset in relation to the rest
11. Graining (grain lines) - correct answer -visible shadow like lines in a
diamond caused by irregularities in the crystal structure
12. Habit - correct answer -characteristic crystal shape of a specific
material
13. Macle - correct answer -a flat, triangular twinned diamond crystal
14. Singly refractive(isotropic) - correct answer -possessing the same
, physical or optical properties in all crystal directions
15. Specific gravity - correct answer -ratio of the weight of a material
to that of an equal volume of water
16. Tetrahedron - correct answer -in diamond, a group of five carbon
atoms with one at the center
17. Thermal conductivity - correct answer -the relative ability of a material
to transfer heat
18. Thermal expansion - correct answer -capcity of a material to expand
when its heated
19. Trace elements - correct answer -atoms in a gem that arent part of its
essential chemical composition
20. Twinned crystal - correct answer -crystal distorted during growth,
with two or more intergrown crystals with opposing crystal directions
21. Unit cell - correct answer -smallest group of atoms with the
, characteristic chemical composition and the basic crystal structure of a
mineral
22. The crystal places most suitable for cleaving a diamond are the... -
correct answer -octahedral planes
23. Squares or rectangles, trigons and parallel groves are types of... -
correct answer -growth marks
24. Which is the softest crystal direction in a diamond? - correct answer -
dodecahedral
25. Crystal shape is an important factor in the evaluation of rough
because... - correct answer -it affects the amount of weight retained
after cutting
26. The habit of a gem quality diamond is the... - correct answer
-octahedron
27. Another name for the cubic crystal system is... - correct answer -
isometric
