Rocks and Minerals Question Marathon

[quizbowl]

Topaz?
Topaz is formed from high temperature fluorine rich waters precipitating in cavities, veins or pigmatities in granites and ryholites.
because of it beging transclucent and blue. It didn't look like it could be any other type of mineral

Not topaz! I also thought it would be that, but it isn't :/

[hexagonaria]

I bet it's (Click to Show Hidden Text)

selenite gypsum. 
Formed as an evaporite deposit in arid conditions. It's used as the main ingredient in plaster products. 
What gave it away was mostly the crystal system.. Only so many things with a monoclinic structure, and colorless.

[quizbowl]

I bet it's (Click to Show Hidden Text)

selenite gypsum. 
Formed as an evaporite deposit in arid conditions. It's used as the main ingredient in plaster products. 
What gave it away was mostly the crystal system.. Only so many things with a monoclinic structure, and colorless.

Not that either!

[tuftedtitmouse12]

Hm... (Click to Show Hidden Text)

Hematite?
Usually of sedimentary origin. Sometimes found in metamorphic rocks from contact metamorphism.
Major ore of Iron
Because it's shiny silver-greyish and crystalled.

[quizbowl]

Hm... (Click to Show Hidden Text)

Hematite?
Usually of sedimentary origin. Sometimes found in metamorphic rocks from contact metamorphism.
Major ore of Iron
Because it's shiny silver-greyish and crystalled.

???

[tuftedtitmouse12]

...If it's not hematite, pay no attention...

[hexagonaria]

let's try again... (Click to Show Hidden Text)

barite?
I've seen colorless barite crystals before, so I guess it's really just a memorization thing for me.
It's used in the manufacturing of glasses and paints, and also in oil well mud.
It can be formed in hydrothermal replacement deposits.

[Allinea]

Since no one seems to have it yet, I might as well give a guess:

Meh (Click to Show Hidden Text)

Halite
Forms by evaporation of water
Main use is table salt
Eh... mainly a random guess but the blue color? IDRK

[quizbowl]

Nope! At this point, I'll just answer it with the ID (you guys can infer the rest without my help )

Hola, me llamo (Click to Show Hidden Text)

Apatite (for whoever said topaz, that's what I initially said, I always get these two mixed up :[

And a new image for y'all:

>.> <.< (Click to Show Hidden Text)

[img]http://i.imgur.com/pOiqK.jpg[/img]
Uses?

[aznluvsricemhm]

Hm....Maybe it's Epidote or Tremolite? Epidote is used for semi-precious gemstones And Tremolite is used for asbestos, fireproofing,and electrical insulators


I'm really sorry....I don't really remember how to hide my answer.