The five physical properties of rocks are color, luster, shape, texture and pattern. Not all rocks have the fifth property of pattern. These properties are visible and/or tactile.
The color of a rock describes the hue or tone of the rock. Black, red, green or blue may be used to describe the color. Color is commonly one of the first things noticed about a rock.
Luster is how a rock shines. If it doesn't shine, it is considered dull. Some rocks look silky, greasy or waxy. To describe this property, it is helpful to have a rock properties chart handy to get the exact texture needed to identify the rock.
The shape of the rock may be round, square or rectangular. Some rocks form in distinctive shapes, while others do not. In some types of rocks, such as sedimentary, shape may be used to describe the shape of the sediments within the rock.
Texture explains how a rock feels. Smooth, rough, hard or soft are common descriptions. The texture of some rocks can be determined by looking at the rock as well as feeling it. It may look smooth or rough and feel the same way.
Pattern is how the layers of rock look together. A striped pattern, for example, may be used to describe a sedimentary rock. If there is no pattern, this property may not be mentioned in the rock's description.