The New Childrens Encyclopedia

40

Rock and mineral guide

Collecting rocks and minerals can be a rewarding

hobby. Rocks are identified by features like color,

texture, and mineral content. Minerals are classified

by crystal structure, hardness, and how they break.

Kimberlite

Anorthosite

Obsidian

Pegmatite

Peridotite

Pumice

Chalk Limestone Conglomerate

Quartzite Marble Serpentinite Schist Gneiss

Slate

Siltstone Tillite

IGNEOUS ROCKS

METAMORPHIC ROCKS

SEDIMENTARY ROCKS

= fine

= medium

= coarse

Rocks are graded by the size

of their grains, as either fine,

medium, or coarse. The size

limits for each category vary

depending on whether rocks

are igneous, metamorphic, or

sedimentary ( p.38).

KEY

F

F

F

MC

F MC

C

C

F

FM F MC CC

MF F MC F MC

M

C

F

MC MC

C Granite

EARTH