2.1 The rock cycle describes how rocks form and change over time.

2.1 What are Rocks and Minerals?  Minerals – pure, naturally, occurring solid materials that are the building blocks of rock; all rocks are made of minerals  Properties – features that a material or object has.

Minerals of Canada Minerals of Canada

 Clues to mineral identification include: –1) Colour – property used to classify and identify rocks and minerals, but colour is not enough to identify a mineral. –2) Lustre – the way the surface of a mineral looks like in the light. –3) Streak – colour of the powder that a mineral leaves behind when you rub it across a rough surface.

–4) Cleavage – the split of a mineral into two smooth surfaces. –5) Fracture – mineral breakage into rough and uneven surfaces. –6) Hardness – measure of a mineral’s hardness according to Moh’s scaled of hardness; harder mineral leave a scratch on the softer ones.

 Moh’s Scale of Hardness – method of ranking how hard a mineral is.  Pg 372 – description of Moh’s scale of hardness

 One determines the hardness of a mineral by rubbing it against a mineral of known hardness.  One will scratch the other, unless they have the same hardness.  For example, your fingernail has a hardness of 2.5 and can easily scratch gypsum with a hardness of 2.  However, you will not be able to scratch a copper penny whose hardness is 3.  However, you will not be able to scratch a copper penny whose hardness is 3.

 Hardness of some other items:  2.5 Fingernail  2.5–3 Gold, Silver  3 Copper penny  Platinum  4-5 Iron  5.5 Knife blade  6-7Glass  6.5 Iron pyrite  7+Hardened steel file