Glossy dark color stone with sharp edges.

Question

Which characteristics describe this rock sample? Check all that apply.

evidence of rapid cooling
evidence of slow cooling
small crystals
large crystals
smooth texture
coarse texture

Answer 1

Based on the description of a glossy dark color stone with sharp edges, the following characteristics would likely apply:

1. Evidence of rapid cooling - The glossy appearance and sharp edges suggest that the rock cooled quickly, which is indicative of an igneous rock formed from lava, possibly as an extrusive rock.

2. Small crystals - Rapid cooling typically results in small or no crystals, supporting the idea that this rock has small crystals (if any).

3. Smooth texture - The glossy finish also indicates a smooth texture, which can be related to rapid cooling.

Do not check the following characteristics:

• Evidence of slow cooling - This would typically lead to larger crystals, which contradicts the description.
• Large crystals - Again, large crystals would suggest slow cooling.
• Coarse texture - A coarse texture is associated with slow cooling and would not apply to this rock described as glossy with sharp edges.

So, you should check:

• Evidence of rapid cooling
• Small crystals
• Smooth texture