Identifying Minerals Chapter 3 Section 2

Objectives 1. Classify minerals using common mineral-identification techniques. 2. Explain special properties of minerals.

Mineral Identification Scientists can use _______________ of minerals to identify them. Color Luster Streak Cleavage Fracture Hardness Density physical properties

Color Color – can sometimes be used to identify minerals but is not always helpful. Some minerals have many different varieties of color. Example: Quartz (rose, clear, smoky) ***Color is ______________ a reliable indicator of a minerals identity. not usually

Luster The way a surface reflects light. A minerals luster can be classified as: Metallic Submetallic Nonmetallic Page 64 in your text book.

Streak The color of a mineral in powdered form. more reliable ____________________ To find out the streak of a mineral it is rubbed against a piece of unglazed porcelain called a streak plate. The streak is not always the color of the mineral. ***Streak is _________________ than color for identification of minerals. powdered form. more reliable

Cleavage and Fracture along flat surfaces curved or irregular surfaces Cleavage – the tendency of some minerals to break ______________________. Fracture – the tendency of some minerals to break unevenly along _____________________ ____________ along flat surfaces curved or irregular surfaces

Hardness – Mohs Hardness Scale German Scientist Friedrich __________ developed a hardness scale: The lower the hardness number the _________ the mineral. The higher the number the __________ the mineral. softer harder

If you have a mineral that is scratched by topaz and apatite, but scratches calcite, then what is the hardness of the mineral? ________ What could the mineral be? ___________ Four Fluorite

SOL Sample Question C

Density specific gravity D= m/v can be used to identify minerals. Usually expressed as a _________________. Ratio of the density of the mineral to the density of water (which is 1). A mineral with a specific gravity of 4 has a density that is 4 times greater than water. specific gravity

Special Properties of Minerals