non silicates - sulfates

Question 1

which sulfates do you need to know for the exam?

Answer 1

1. anhydrite
2. gypsum
3. Chalcoalumite
4. Barite

Question 2

identify the following mineral: 
habit:
- acicular 
aggregation:
- granular, cab be radial 
colour:
- white/clear 
- white streak 
lustre:
- silky/pearly
 cleavage: 
- three directions 
- one well developed, the other two poor 
hardness: 
2

Answer 2

gypsum

Question 3

gypsum and halite share the follwing properties:
hardness: 2 
Colour: white/transparent 
cleavage: three directions. 
how could you tell them apart?

Answer 3

• halite tastes like salt

- gypsum has acicular habit whereas halite has cubic

Question 4

identify the following mineral:
habit:
- prismatic/elongated 
colour:
-white
-no streak
lustre:
-greasy, vitreous, pearly
clevage:
- three when well formed

Answer 4

anhydrite

Question 5

anhydrite and gypsum can appear VERY similar, how would you distinguish between the two?

Answer 5

the hardness, as anhydrite has a hardness 3/4 whereas gypsum has a hardness 2

Question 6

what does the barite specimine look like and which group does it belong to?

Answer 6

rosy pink to white with sheets going in one clear direction.

sulfates