Slate

http://library.thinkquest.org/05aug/00461/images/slate.jpg

http://commons.wikimedia.org/wiki/Image:SlateUSGOV.jpg

Slate: 1. Slate splits into perfectly cleaved, broad thin layers. 2. In the formation of slate, pressure causes the flaky minerals within the sedimentary rock, such as mica, clay, and chlorite, to be reoriented. 3. the flat faces of the minerals lie at right angles to the source of the pressure, and the planes of easy cleavage are also at right angles to the source of the pressure. 4. Slate is a fine-grained, foliated, metamorphic rock 5. Slate is frequently grey in colour especially when seen en masse covering roofs.

Where it forms :
 * IT forms manly on wet lands sometimes they are found on dry land.

Use of the rock: 1. roof 2. thin sheets 3.whetstone to hone knives 4.laboratory bench tops 5.billiard table tops

Color: 1. Gary somtimes goes a little black

brian