Presentation on theme: "Warm Up 9/27 The most common mineral group in Earth’s crust is the ____________. a. Carbonates c. Oxides b. Silicates d. Sulfides What are the building."— Presentation transcript:
1 Warm Up 9/27The most common mineral group in Earth’s crust is the ____________.a. Carbonates c. Oxidesb. Silicates d. SulfidesWhat are the building blocks of minerals?a. Elements c. Rocksb. Electrons d. IsotopesThe building block of the silicate minerals is called the _______________.a. Silicon-aluminum triangleb. Aluminum-oxygen tetrahedronc. Silicon-oxygen tetrahedrond. Silicon-oxygen triangleAnswers: 1) b. 2) a. 3) c.
3 ColorSmall amounts of different elements give the same mineral different colorsThis property is not often used to identify minerals
4 Streak Streak is the color of a mineral in its powdered form Streak is obtained by rubbing a mineral across a streak plateThe streak’s color never varies between different colors of a mineralCan also see the differences between minerals with metallic lusters and minerals with nonmetallic (no streak is produced)
5 LusterLuster is used to describe how light is reflected from the surface of a mineralMinerals that have the appearance of metals have metallic lustersMinerals with a nonmetallic luster are described with many different adjectives (glassy, pearly, silky, earthy, brilliant)
7 Crystal FormCrystal form is the visible expression of a mineral’s internal arrangement of atomsWhen a mineral develops slowly, it will form a well-defined crystalMost of the time, minerals are competing for space, resulting in an intergrown crystal structure
9 Concept CheckWhat two conditions produce crystals with well-defined faces?Unrestricted space and a slow rate of formation
10 HardnessHardness – a measure of the resistance of a mineral to being scratchedThe Mohs scale consists of 10 minerals arranged from 10 (hardest) to 1 (softest)Diamond, the hardest mineral on Earth, can scratch anythingYou can use your fingernail, copper plate, glass, quartz, etc.
12 Concept CheckWhat are three of the most useful properties for identifying unknown minerals?Hardness, streak, and luster
13 CleavageCleavage is the tendency of a mineral to cleave, or break, along flat, even surfacesSome minerals have structures which allow them to break easily into sheets (mica)Other minerals have very strong bonds, and fracture instead
15 FractureMinerals that do not show cleavage when broken are said to fracture (the uneven breakage of a mineral)
16 Concept Check How are cleavage and fracture different? Cleavage is the tendency for a mineral to break along flat, even surfaces. Fracture is the uneven breakage of a mineral.
17 Density (d) = mass (m) / Volume (V) Density is the property of all matter that is the ratio of an object’s mass to its volumeDensity (d) = mass (m) / Volume (V)Density is usually expressed in g/cm3 in GeologyMany common minerals have densities between 2 and 5 g/cm3The density of a pure mineral is a constant value, and can be used to determine the purity or identity of some minerals
18 Distinctive Properties of Minerals Some minerals can be recognized by other distinctive propertiesSome minerals are magnetic, some you can see through, some streaks smell like rotten eggs, and some will bubble when acid is placed on themA mineral’s properties depend on the elements that compose the mineral (its composition) and its structure (how its atoms are arranged)
19 Assignment Read Chapter 2, Section 3 (pg. 50-55) Do Section 2.3 Assessment #1-6 (pg. 55)Study for the Chapter 2 Quiz!