physical properties of minerals

Cleavage

The tendency of a mineral to break along planes of weakness. Minerals with excellent strength ___ will break into smooth, flat, parallel surfaces. A good ___ will result in small, smooth, steplike flat surfaces.

Luster

a mineral describes the appearance of light as it is reflected off its surface. A mineral may be described as metallic, like that of a polished metal.

Color

Although ___ is the most obvious mineral property, it is not a reliable feature for identifying minerals because it can be altered by chemical impurities within its structure.

Streak

the color of a mineral in its powdered form. It can be obtained by rubbing the mineral on an abrasive ceramic tile called streak plate.

hardness

a measurement of the strength of the chemical bonds in its structure. It can be measured by scratching it with another mineral or a reference material with known ____.

Density

measure of the density of a mineral. It is the weight of a mineral relative to the weight of an equal volume of water. Most common minerals have a specific gravity of 2.7, while gold has 19.