EOSC 118: Module B - Precious Gemstones
Part 2 ACTUAL QUESTIONS AND
CORRECT ANSWERS
What are three common pegmatite gems? - CORRECT ANSWERS✅✅- tourmaline
- topaz
- spodumene
How did the word tourmaline originate? - CORRECT ANSWERS✅✅- roots in the sinhalese
word "turamali" which translates to "stone with many colours"
- gemstone is known for its diverse colour range and its diverse colour range in single crystals
How did the word Topaz originate? - CORRECT ANSWERS✅✅- Thought that the word
was applied to a variety of gemstones such a peridot, aquamarine, or citrine
- name likely comes from the island of Zabargad formerly known as Topazos (classic source
of peridot not topaz)
How do spodumenes gem varieties "kunzite" and "hiddenite" names originate? - CORRECT
ANSWERS✅✅- named after individuals
- AE Hidden recognized green spodumene gem in north carolina
- GF Kunz, famous mineralogist had gem named after him
What is the most common colour of tourmaline? - CORRECT ANSWERS✅✅- opaque
black
, Why is tourmaline referred to as a "garbage can element" - CORRECT ANSWERS✅✅-
because so many elements can enter its structure
How is tourmaline distinguished from other minerals? - CORRECT ANSWERS✅✅-
recognized by its crystal shape (psuedo-hexagonal outline, stritrations)
- its association with pegmatite minerals
- its strong dichroism (colour is much diff across the long axis)
- refractive index and SG
How large can topaz crystals get? - CORRECT ANSWERS✅✅- can reach up to 10m long
and 3m across weighing up to 350 tonnes, (not gem quality obviously)
- gem quality topaz has been found up to several hundred kg
Where is the largest gem topaz from? - CORRECT ANSWERS✅✅- Ouro Preto Brazil
- weights 22,892.5 carats and is hosted in the Smithsonian Institution National Museum of
Natural history
What are the most common colours of topaz? - CORRECT ANSWERS✅✅- colourless,
lightly coloured brown, blue, and yellow
What are the rarest colours of topaz? - CORRECT ANSWERS✅✅- Pink and orangey-red
How does the colour from topaz generate? - CORRECT ANSWERS✅✅- unlike most other
minerals
- generated from colour centers
Part 2 ACTUAL QUESTIONS AND
CORRECT ANSWERS
What are three common pegmatite gems? - CORRECT ANSWERS✅✅- tourmaline
- topaz
- spodumene
How did the word tourmaline originate? - CORRECT ANSWERS✅✅- roots in the sinhalese
word "turamali" which translates to "stone with many colours"
- gemstone is known for its diverse colour range and its diverse colour range in single crystals
How did the word Topaz originate? - CORRECT ANSWERS✅✅- Thought that the word
was applied to a variety of gemstones such a peridot, aquamarine, or citrine
- name likely comes from the island of Zabargad formerly known as Topazos (classic source
of peridot not topaz)
How do spodumenes gem varieties "kunzite" and "hiddenite" names originate? - CORRECT
ANSWERS✅✅- named after individuals
- AE Hidden recognized green spodumene gem in north carolina
- GF Kunz, famous mineralogist had gem named after him
What is the most common colour of tourmaline? - CORRECT ANSWERS✅✅- opaque
black
, Why is tourmaline referred to as a "garbage can element" - CORRECT ANSWERS✅✅-
because so many elements can enter its structure
How is tourmaline distinguished from other minerals? - CORRECT ANSWERS✅✅-
recognized by its crystal shape (psuedo-hexagonal outline, stritrations)
- its association with pegmatite minerals
- its strong dichroism (colour is much diff across the long axis)
- refractive index and SG
How large can topaz crystals get? - CORRECT ANSWERS✅✅- can reach up to 10m long
and 3m across weighing up to 350 tonnes, (not gem quality obviously)
- gem quality topaz has been found up to several hundred kg
Where is the largest gem topaz from? - CORRECT ANSWERS✅✅- Ouro Preto Brazil
- weights 22,892.5 carats and is hosted in the Smithsonian Institution National Museum of
Natural history
What are the most common colours of topaz? - CORRECT ANSWERS✅✅- colourless,
lightly coloured brown, blue, and yellow
What are the rarest colours of topaz? - CORRECT ANSWERS✅✅- Pink and orangey-red
How does the colour from topaz generate? - CORRECT ANSWERS✅✅- unlike most other
minerals
- generated from colour centers
