Minerals Identification

So far the mineral you are identifying is a Dark colored non-metallic mineral.

To continue identifying a mineral you must now describe its hardness by selecting the appropriate link in the menu on the left.

Hardness

The hardness of a mineral is a measure of the mineral’s resistance to abrasion and therefore a measurement of the strength of the chemical bonds between the individual atoms or molecules within the mineral.

The strength of the bonds depends solely on the physical properties of the atoms within the bond. With over 2000 known minerals, each of which has its own definite chemical composition, using hardness as an identifying property could be a daunting task. This process is simplified by using a relative scale such as Mohs Scale of Hardness.

Mohs Hardness		Common Objects
10	Diamond
9	Corundum
8	Topaz
7	Quartz
		6.5- Streak Plate
6	Orthoclase Feldspar
5	Apatite	5.5- Glass or knife blade
4	Flourite	4.5- Iron Nail
3	Calcite	3.5- Copper penny
2	Gypsum	2.5- Fingernail
1	Talc

To use this technique, hardness values between 1 and 10 have been assigned to some common minerals. 1, the softest, is a mineral known as talc; the hardest mineral, 10 on Mohs scale, is diamond. Along with assigning hardness values to common minerals, these values have also been assigned to other common objects as illustrated below.

Minerals or objects that have higher hardness values will be able to scratch minerals or objects of lesser hardness values. Therefore fluorite, hardness 4, will be scratched by any mineral with hardness greater than 4 as well as by an iron nail.

To determine the hardness of a mineral, start by scratching it with your fingernail then use progressively harder and harder objects until the mineral scratches. You will then be able to narrow down the hardness of the mineral to a hardness range.

 

 

Once you have determined your minerals hardness click on the appropriate link in the menu on the left.