EOSC 118: Module B - Precious Gemstones
ACTUAL QUESTIONS AND CORRECT
ANSWERS
How did the word diamond originate? - CORRECT ANSWERS✅✅- from the greek word
"adamao" (translates to "I tame/"I subdue")
- used to describe items of great hardness
Where were diamonds first found? - CORRECT ANSWERS✅✅- India was where the first
appreciation of diamond mining occurred
- Sanskrit name; "vajra"
- earliest records of this word was 4th century BC
- Indian diamonds were of euhedral diamond shape (octahedrons)
When and where did diamonds begin being faceted? - CORRECT ANSWERS✅✅- began in
the 13th-14th century
- likely began being faceted in Venice or Antwerp
When did non-royal individuals begin to adorn jewellery w/ diamonds? - CORRECT
ANSWERS✅✅- around the 17th century
- usually the wealthy upper-class interested in showcasing their power
What is the brilliant cut? - CORRECT ANSWERS✅✅- designed to enhance the beauty not
power of the stone
- maximized the outward fire and brilliance of the diamond at the expense of total weight
When did diamond cutting and jewellery take a turn? - CORRECT ANSWERS✅✅during
the 17th century, diamonds began becoming the center of attention rather than the piece of art
that they were hosted in
- caused diamond cutting to become more important
,Brief history of diamond locations? - CORRECT ANSWERS✅✅- first discovered in the
Golconda region of India
- discovered in Brazil by the 18th century (small amounts)
- discovery of diamond-bearing kimberlite at Kimberley, South Africa in 1867
Basic info on Kimberly Mine South Africa? - CORRECT ANSWERS✅✅- Allowed for
diamonds to more commonly come into the hands of royalty and wealthy
- Originally, the discoveries were made by individuals
- De Beers took over in 1888 and changed the dynamic
Details about De Beers and Kimberly Mine? - CORRECT ANSWERS✅✅- After 20th
century, controlled most of diamond industry
- producing nearly 250,000 carats from the outset
- by early 1900s, producing 3 million carats annually
- today (2020) De Beers production is 23%
What does the Kimberly Process do? - CORRECT ANSWERS✅✅- monitors the
import/export activity of countries, keeping tabs on diamond legitimacy
- estimated less than 1% of global diamond comprises of stones sourced from conflict zones
(no Kimberly process)
What is diamond and its basic qualities? - CORRECT ANSWERS✅✅Pure carbon packed
into a dense crystalline structure
- Density: (3.51g/cm^3)
- Hardness: 10 (Mohs hardness scale)
- high durability
- high refractive index of 2.42
- exhibits great dispersion
- has cubic symmetry
- has perfect octahedral cleavage
What colour is pure diamond? - CORRECT ANSWERS✅✅- colourless
,- rare structural defects, elemental substitutions, or lab procedures can change the colour
What are the 4 C's of diamonds? - CORRECT ANSWERS✅✅- Cut
- Clarity
- Carat
- Colour
- *****Country
What are diamond characteristics that stand out? - CORRECT ANSWERS✅✅- Very high
thermal conductivity
- Poor electrical conductivity
- Diamond is an insulator (high resistivity), Maisonette a semi conductor
Why does diamond have high thermal conductivity? - CORRECT ANSWERS✅✅- due to
the covalent bonding that holds its carbon atoms together
- thermal conductivity 3x higher than gold and silver
Is ionic bonding or covalent bonding more common in minerals in nature? - CORRECT
ANSWERS✅✅- Ionic bonding more common in nature
What crystal system does diamond belong to? - CORRECT ANSWERS✅✅- Isometric or
cubic crystal system
- Unit cell building blocks are cubes
- Very strong covalently bonded carbon atoms in highly symmetrical 3D network
What is diamond cleavage like? - CORRECT ANSWERS✅✅- diamonds have perfect
cleavage
- diamond cleavage planes intersect to form the shape of a octahedron
- diamonds weakness
What is graphite? - CORRECT ANSWERS✅✅- Composed entirely of carbon (similar to
diamonds)
, - has a significantly different crystal structure and different physical properties
- Bonds are Van der Waals bonds (weak chemical bond)
Why is graphite used as pencil lead? - CORRECT ANSWERS✅✅- Because graphites bonds
are van der waals bonds which are a very weak chemical bond
What is polymorphism? - CORRECT ANSWERS✅✅- Material being of the same
composition but having a different crystal structure
- ex. diamond and graphite are polymorphs w/ the composition of carbon
What are the two base subdivisions of diamonds? - CORRECT ANSWERS✅✅Based on
amount of nitrogen that has been substituted in crystal structure
- type i diamonds: have N concentration greater than 10ppm (N impurities)
- type ii diamonds: have N less than 10ppm (nitrogen free) (No N impurities)
What are the further subdivisions of type i diamonds? - CORRECT ANSWERS✅✅- type ia:
where N atoms occur in aggregates within the diamond, lots of N in crystal structure (N
impurities)
- type ib: where N in the diamond structure is disperesed, scattered about crystal lattice
(isolated single N impurities)
What are the further subdivisions of type ii diamonds? - CORRECT
ANSWERS✅✅diamonds w/ little to no N in crystal structure
- type iia: those that are boron (B) and nitrogen (N) free (no N or B impurities)
- type iib: those that contain minute amount of boron (B), up to 10ppm (boron impurities)
Can type ia diamonds be further subdivided? - CORRECT ANSWERS✅✅type ia diamond:
where N atoms occur in aggregates within the diamond (lots of N in crystal structure)
- type iaA: with paired N atoms
- type iaB: where 4 N atoms are clustered often w/ a vacancy (void of atoms) at their center
How rare is each diamond type? - CORRECT ANSWERS✅✅- type ia most common (~98%
of all diamonds), yellow hue
ACTUAL QUESTIONS AND CORRECT
ANSWERS
How did the word diamond originate? - CORRECT ANSWERS✅✅- from the greek word
"adamao" (translates to "I tame/"I subdue")
- used to describe items of great hardness
Where were diamonds first found? - CORRECT ANSWERS✅✅- India was where the first
appreciation of diamond mining occurred
- Sanskrit name; "vajra"
- earliest records of this word was 4th century BC
- Indian diamonds were of euhedral diamond shape (octahedrons)
When and where did diamonds begin being faceted? - CORRECT ANSWERS✅✅- began in
the 13th-14th century
- likely began being faceted in Venice or Antwerp
When did non-royal individuals begin to adorn jewellery w/ diamonds? - CORRECT
ANSWERS✅✅- around the 17th century
- usually the wealthy upper-class interested in showcasing their power
What is the brilliant cut? - CORRECT ANSWERS✅✅- designed to enhance the beauty not
power of the stone
- maximized the outward fire and brilliance of the diamond at the expense of total weight
When did diamond cutting and jewellery take a turn? - CORRECT ANSWERS✅✅during
the 17th century, diamonds began becoming the center of attention rather than the piece of art
that they were hosted in
- caused diamond cutting to become more important
,Brief history of diamond locations? - CORRECT ANSWERS✅✅- first discovered in the
Golconda region of India
- discovered in Brazil by the 18th century (small amounts)
- discovery of diamond-bearing kimberlite at Kimberley, South Africa in 1867
Basic info on Kimberly Mine South Africa? - CORRECT ANSWERS✅✅- Allowed for
diamonds to more commonly come into the hands of royalty and wealthy
- Originally, the discoveries were made by individuals
- De Beers took over in 1888 and changed the dynamic
Details about De Beers and Kimberly Mine? - CORRECT ANSWERS✅✅- After 20th
century, controlled most of diamond industry
- producing nearly 250,000 carats from the outset
- by early 1900s, producing 3 million carats annually
- today (2020) De Beers production is 23%
What does the Kimberly Process do? - CORRECT ANSWERS✅✅- monitors the
import/export activity of countries, keeping tabs on diamond legitimacy
- estimated less than 1% of global diamond comprises of stones sourced from conflict zones
(no Kimberly process)
What is diamond and its basic qualities? - CORRECT ANSWERS✅✅Pure carbon packed
into a dense crystalline structure
- Density: (3.51g/cm^3)
- Hardness: 10 (Mohs hardness scale)
- high durability
- high refractive index of 2.42
- exhibits great dispersion
- has cubic symmetry
- has perfect octahedral cleavage
What colour is pure diamond? - CORRECT ANSWERS✅✅- colourless
,- rare structural defects, elemental substitutions, or lab procedures can change the colour
What are the 4 C's of diamonds? - CORRECT ANSWERS✅✅- Cut
- Clarity
- Carat
- Colour
- *****Country
What are diamond characteristics that stand out? - CORRECT ANSWERS✅✅- Very high
thermal conductivity
- Poor electrical conductivity
- Diamond is an insulator (high resistivity), Maisonette a semi conductor
Why does diamond have high thermal conductivity? - CORRECT ANSWERS✅✅- due to
the covalent bonding that holds its carbon atoms together
- thermal conductivity 3x higher than gold and silver
Is ionic bonding or covalent bonding more common in minerals in nature? - CORRECT
ANSWERS✅✅- Ionic bonding more common in nature
What crystal system does diamond belong to? - CORRECT ANSWERS✅✅- Isometric or
cubic crystal system
- Unit cell building blocks are cubes
- Very strong covalently bonded carbon atoms in highly symmetrical 3D network
What is diamond cleavage like? - CORRECT ANSWERS✅✅- diamonds have perfect
cleavage
- diamond cleavage planes intersect to form the shape of a octahedron
- diamonds weakness
What is graphite? - CORRECT ANSWERS✅✅- Composed entirely of carbon (similar to
diamonds)
, - has a significantly different crystal structure and different physical properties
- Bonds are Van der Waals bonds (weak chemical bond)
Why is graphite used as pencil lead? - CORRECT ANSWERS✅✅- Because graphites bonds
are van der waals bonds which are a very weak chemical bond
What is polymorphism? - CORRECT ANSWERS✅✅- Material being of the same
composition but having a different crystal structure
- ex. diamond and graphite are polymorphs w/ the composition of carbon
What are the two base subdivisions of diamonds? - CORRECT ANSWERS✅✅Based on
amount of nitrogen that has been substituted in crystal structure
- type i diamonds: have N concentration greater than 10ppm (N impurities)
- type ii diamonds: have N less than 10ppm (nitrogen free) (No N impurities)
What are the further subdivisions of type i diamonds? - CORRECT ANSWERS✅✅- type ia:
where N atoms occur in aggregates within the diamond, lots of N in crystal structure (N
impurities)
- type ib: where N in the diamond structure is disperesed, scattered about crystal lattice
(isolated single N impurities)
What are the further subdivisions of type ii diamonds? - CORRECT
ANSWERS✅✅diamonds w/ little to no N in crystal structure
- type iia: those that are boron (B) and nitrogen (N) free (no N or B impurities)
- type iib: those that contain minute amount of boron (B), up to 10ppm (boron impurities)
Can type ia diamonds be further subdivided? - CORRECT ANSWERS✅✅type ia diamond:
where N atoms occur in aggregates within the diamond (lots of N in crystal structure)
- type iaA: with paired N atoms
- type iaB: where 4 N atoms are clustered often w/ a vacancy (void of atoms) at their center
How rare is each diamond type? - CORRECT ANSWERS✅✅- type ia most common (~98%
of all diamonds), yellow hue
