This Rocks! Poem by Douglas Nichols

A rock is a rock,
It may be deduced.
But there are three different forms,
Depending on how their produced.

Sedimentary is one form.
Common types being sandstone and clay.
It's fairly soft and can crumble easily,
Covering 75% of the earth's surface, by the way.

It is formed from different particles.
In settled layers it is laid.
Compacting into a solid form,
Where fossils can be displayed.

One kind in particular,
Of calcium carbonate it is comprised.
Derived from dead oceanic organisms,
Thus limestone is materialized.

Igneous is another form.
Magma comes from within the earth.
It cools and hardens below or on the surface,
Thus consummating this rocks birth.

In lava that cools quickly,
Crystallization does not occur.
It is glass-like and really shiny,
Called obsidian, that's for sure!

The magma that lies deeper,
Has larger crystals in the making.
It's much slower in it's cooling,
Forming granite, there's no mistaking.

The final form is metamorphic.
Intense heat and pressure are the key.
Of transforming any rock form,
Into a different rock you see.

Some look squished, or smeared, or folded,
Or have stripes paralleled inside.
Precious gems can be the outcome.
Deep in the earth they like to hide.

The variety is truly endless.
Between the various rock forms, all three.
They beautify and make up this fine world.
Enriching life for you and me.