Rocks & Minerals B/C

[SenseiSushi]

Short Event Description: "Teams will use their knowledge of rocks and minerals to identify pictures/specimens and complete a written test."

What type of cleavage is present in obsidian?

[Magikarpmaster629]

Trick question!
None. It's a rock, not a mineral.

[bhavjain]

I'm gonna go since nobody posted yet

Identify the following, classify it as a mineral, or rock. If it is a mineral, give its chemical structure. What is responsible for the color patterns?

Image (Click to Show Hidden Text)

[img]https://s-media-cache-ak0.pinimg.com/564x/8d/f6/0c/8df60cd7820274f2020a8b43d6c54b9f.jpg[/img]

[a boy]

xd (Click to Show Hidden Text)

[list][*]1. Opal (mineral) [*]2. SiO2 * nH2O [*]3. Internal structure diffracts light, causing it to display many colors at once[/list]

[bhavjain]

a boy Correct. Your turn.

[bhavjain]

I'm gonna go since a boy didn't post.

Just ID (Click to Show Hidden Text)

[img]https://s-media-cache-ak0.pinimg.com/736x/ff/30/23/ff302376f5388ded0ea94746487a472c.jpg[/img]

[Cherrie_Lan]

Corundum?

[bhavjain]

Cherrie_Lan Incorrect.

[asthedeer]

I'm gonna go since a boy didn't post.

Just ID (Click to Show Hidden Text)

[img]https://s-media-cache-ak0.pinimg.com/736x/ff/30/23/ff302376f5388ded0ea94746487a472c.jpg[/img]

I'm guessing...because I haven't done R&M in literally 2 years (Click to Show Hidden Text)

The first thought I had was tourmaline, but maybe it's beryl, else I'm completely wrong :P

[bhavjain]

asthedeer Tourmaline is correct, specifically liddicoatite. Anyone know if we have to know the specific minerals of the Tourmaline group?