What determines if something is a mineral? inorganic Naturally occurring solid Crystal structure definite chemical make-up Video clip “What is a mineral?’ Media player quicktime
What do you think? Which of these are minerals? gold water coal rubies petroleum diamonds Here is a hard one – What about ice? All minerals have a definite chemical combination – view media player video Same video - quicktime
How do geologists identify minerals? One way is color! http://www.minresco.com http://www.gems-afghan.com http://www.globalcrystals.com http://www.prettyrock.com
A mineral's hardness helps identify it. Not all minerals have the same hardness. Some you can easily scratch with your fingernail! http://www.infowest.com /vwdocs/vwlessons http://www.prettyrock.com http://www.wpclipart.com http://www.wpclipart.com
Streak test http://www.uky.edu/KGS Streak is the color of a mineral powder. Many minerals appear a different color when powdered than they do as a big piece. The color may be entirely different, or it may be a different shade. http://cmsc.minotstateu.edu http://cmsc.minotstateu.edu
Minerals also have different densities. This means for equal size, they have their own special weight. http://www.palagems.com Which one is worth more? How could you tell? The first one is topaz (worth a lot) and the second is citrine quartz (not worth a lot). A scientist would measure their densities and they would be different!
Another property is the way a mineral breaks. Cleavage means it breaks the same way every time. Fracture means it breaks in a random pattern that cannot be predicted. www.mrsciguy.com Calcite and halite break a special way. donsmaps.com www.visionlearning.com Quartz and chert break in a random pattern. There is not way to predict how they break.
Minerals have many properties that together help us identify them. Click here for a video clip on mineral properties media player Quicktime Another video clip on identifying minerals Media player Quicktime