My Earth Science

Section 1

What is the difference between a rock and minerals?  What is the difference between a sugar cookie and the flour, sugar, milk and eggs?   The flour, sugar, milk and eggs are the ingredients that are put together to make the final product: the sugar cookie.  The ingredients make the cookie.  A bag of flour is just pure flour, as is a bag of sugar.  The cookie is a mixture. This is the same with rocks and minerals. A mineral is only one thing, it is pure in a way. Gold (Au) is only gold, it is an element. Galena (PbS) is just

This is the same with rocks and minerals. A mineral is only one thing, it is pure in a way. Gold (Au) is only gold, it is an element. Galena (PbS) is just galena, it is a compound of lead (Pb) and sulfur (S) and nothing else – it is pure (PbS).   A rock is a product made from combining different minerals together. A rock is a mixture.

A rock is a product made from combining different minerals together. A rock is a mixture.  Granite is a rock that is made from three different minerals (quartz, biotite mica, and potassium feldspar).

(fig 1.1)

Minerals = pure chemical makeup. Just a single element or compound

Rock = mixture of minerals

Section 2 Mineral definition

To be defined as a mineral it must meet 5 requirements.

1. Solid at room temperature.   
2. Naturally occurring in nature.
3. Inorganic.  
4. Definite chemical makeup.
5. Has a definite crystal structure.

Let’s look deeper into what each item means.

1. Solid at room temperature: a liquid can not be a mineral.  Water is not a mineral.
2. Naturally occurring: it can not be man-made. Glass is made by man so it is not a mineral.  An aluminum soda can is not a mineral – even though the aluminum is a mineral the aluminum can is not because man made the “can”.
3. Inorganic: inorganic means not from a living thing, not a plant or animal. Organic means it is part of life as know it here on earth. Earth has mostly carbon-based life-forms, both plants, and animals.
   Organic: living – from plants or animals
   Inorganic: not living, never had lived, not from plants or animals at all
4. Definite chemical makeup: it is pure elements or pure compound, not a mixture.
5. Has a definite crystal structure: the atoms are arranged and joined in a pattern. The crystal shape is based on the arrangement of the atoms.  There are 6 different shapes and several mineral properties which are determined by the internal arrangement of atoms.

Section 3  Properties used to Identify and Name Minerals 

The definition of a mineral (section 2) can tell us if it is a mineral or not, but it does not tell us which mineral it is. It can not give us a name.

(fig. 3.1)

The definition of a dog is a carnivorous mammal, Canis lupus familiaris. The picture on the right (fig. 3.1) is, by definition a dog. However, we do not know what the dog’s name is yet.

If it has a white tip tail and paws, a white chest and muzzle, and a red collar, it’s name is Rover and it belongs to Jose.

This section is about how to identify and name a mineral.