PROPERTIES OF ROCKS

1. COLORS:  1. Rocks are different colors because they have minerals. The color of the minerals in the rock can turn it brown, red, green or other colors.

2. SIZES: Why are rocks different sizes?  Boulders are the biggest type of rock, to be found on a mountain. A boulder is so big that most humans can't move them on their own.

 A cobble is a rock that is smaller than a boulder and larger than a pebble  A rock is smallest when it is turned into silt. Silt is smaller than sand and often found at the bottom of rivers and streams.

3. SHAPES : 3. Why are rocks different shapes? rocks  Rocks are different shapes because they are hit over and over by water and wind.

4. TEXTURE : Rock's texture—coarse-grained, fine-grained, and glassy are all descriptions of a rock's texture. The texture of igneous rocks can be analyzed to understand how the rock became solid or crystallized from liquid, melted rock.

COARSE-GRAINED

GLASSY TEXTURE

FINE-GRAINED

5. HARDNESS: Rating Description Mineral Example :  1 Very Soft Easily crumbles. Can be scratched with a fingernail (2.2) Talc  2 Soft Can be scratched with a fingernail (2.2) Gypsum, Soapstone

 3 Soft Can be scratched with a copper penny (3.5) Calcite  4 Semi-Hard Can be scratched with a common nail (5.2) Fluorite  5 Hard Can be scratched with a common nail (5.2). Apatite

 6 Hard N. B. Mineral of hardness 6 or more will scratch glass. Feldspar  7 Very Hard Can be scratched with a concrete  8 Very Hard Topaz  9 Extremely Hard Used in industrial tools for cutting, grinding & sanding. Corundum  10 The Hardest Diamond is used to cut all minerals including diamonds. Diamond

6. HEAVINESS  Rocks are measured through their mass. It can be considered light or heavy.