Mineral Property Color Color is the first thing someone notices when they view a mineral. Color is also one of the big reasons that attract people to minerals. Generally speaking, color is not a good property to use to ID a mineral. Color can be confusing. Many minerals have different colors and some minerals' colors are identical to other minerals' colors.

Mineral Property Streak Streak is closely related to color, but is a different property because the color of the mineral may be different than the color of the streak.color Streak is actually the color of the powder of a mineral. It is called streak because the proper way to test for streak is to rub a mineral across a tile of white unglazed porcelain and to examine the color of the "streak" left behind.

Mineral Properties Color & Streak Pyrite (known as "Fool's Gold") is always brassy yellow when found in crystals, even broken crystals, of any size; but when powdered, produces a black streak. Gold's streak, by the way, is yellow! Hematite's streak is blood-red Galena's streak is lead gray

Mineral Property - Luster A mineral’s luster is the way in which light reflects from the surface. The two major types of luster are metallic & nonmetallic.

Some other ways to describe luster are Dull - just a non-reflective surface of any kind Earthy - the look of dirt or dried mud Fibrous - the look of fibers Greasy - the look of grease Gumdrop - the look a sucked on hard candy Metallic - the look of metals Pearly - the look of a pearl Pitchy - the look of tar Resinous - the look of resins such as dried glue or chewing gum Silky - the look of silk, similar to fibrous but more compact Submetallic - a poor metallic luster, opaque but reflecting little light Vitreous - the most common luster, it simply means the look of glass Waxy - the look of wax Transparent – can you see through it?

Quick Check Answer the following: – What is the first thing someone notices about a mineral? – What do we call the color of the powdered mineral? – Which is more reliable: streak or color?

Mineral Property Cleavage (or fracturing) When a mineral breaks it does so either by fracturing or by cleaving.fracturing Cleavage is the tendency of a mineral to break along flat surfaces. Crystal cleavage is a smooth break producing what appears to be a flat crystal face. Fracture is the tendency of a mineral to break into irregular pieces.

Mineral Property How a mineral breaks When a mineral breaks it does so either by fracturing or by cleaving.fracturing Cleavage is the tendency of a mineral to break along flat surfaces. Crystal cleavage is a smooth break producing what appears to be a flat crystal face. Fracture is the tendency of a mineral to break into irregular pieces.

Mineral Property Hardness A mineral’s hardness is its resistance to being scratched. A scale known as the Moh’s scale is often use

Mohs Scale

Mineral Property Density Each mineral has a specific density. Density is the mass of a given space or in scientific terms the mass per unit of volume. For example, if you have two minerals of the same size one might be heavier than the other. The galena will be three times heavier than the same size of quartz.

Mineral Property Density Geologists measure density by the following: – First they use a balance to determine the mass of a sample. – Second, they place the mineral in water to see how much water it displaces. The volume of displace water = the volume of the sample – Third they use the following formula: Density = Mass/Volume

Brain Check Answer the following: – If you break a mineral and it breaks into cubes, is it fracture or cleavage? Why? – If you break a mineral with a hammer and it falls apart into a million different pieces, is it fracture or cleavage? Why? – Name three things you can scratch talc with. – What is the formula for density?

Some minerals have specific properties Fluorescence: some minerals glow when exposed to ultraviolet light Magnetic: Some minerals are attracted to magnets Acid: Some minerals react with acid by bubbling

SLCDFH Some Lumpy Cats Die From Heat Some Llamas Climb Dirty Fat Hills S Streak – Powdered Color L Luster – How shiny C Cleavage – Breaks in sheets or blocks D Density – How much mass in a given volume F Fracture – Just crumbles & breaks H Hardness – Can be scratched by