You have selected fine grains

Updated Thursday, 28th September 2006
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What rocks are these?

You have identified that your sample is a rock.
You have suggested it has a fine grain structure
If this is incorrect, start again or go back one step.

Think now about the colour of your rock. How dark is it?:

It is a light-coloured rock

It is of an intermediate colour

It is a dark-coloured rock

More help with this question:
Rocks come in a multitude of colours, for simplicity we have divided them into three catgories:

Dark coloured rocks: may be black, dark brown, dark grey or dark green.

Intermediate coloured rocks: are pale grey, reddish brown or green.

Light coloured rocks: are pale pink, pale green, light grey or white.

Tip: the colour of a rock can also be influenced by its grain size. Very fine grained rocks often appear much darker than their coarse grained or coarsely crystalline equivalents.

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