color- is usefull to identify some minerals. However, many minerals occur in many different colors, and different
minerals may be the same color. You can see through some minerals, just as you can see through glass. They are transparent.
Some samples of quartz and calcite are like this. A transparent mineral that has nocolor is described as colorless.
hardness- the hardness of a mineral can be found by scratching one mineral against another. the harder mineral leaves
a scratch on the softer one. The hardness of a mineral is measured with a number scale develeped by a German scientist named
Friedrich Mohs. The Mohs hardness scale is a list of 10 minerals ranked in order of hardness. These 10 are used to
compare the hardness of all other minerals found on Earth.
lustre- is a word used to describe how the surface of a mineral reflects light rays to you eye. Some minerals have a
metallic lustre like polished gorld, or steel. Others are called non-metallic. They may have lustre like glass plastic or
oil.
Streak- Describes the color of the powdery mark that some minerals make when thay are scratched against a hard surface.
To see the streak clearly, scratch a mineral against a streak plate. A streak plate is an unpolished pieve of porcelain tile.
The color of the streak may be the same as the color of the mineral, or it may be different. Streak is more constant than
color and is very useful for identifying some minerals.
magnetism- is the ability of the mineral to attract a magnet or compass needle. Magnetism is found only in certain
minerals that contain iron. Magnetism is not found in most minerals, but it is easy to demonstrate.
