MINERALS ARE NATURALLYOCURRING, INORGANIC SOLIDS.
EARTH’S ROCKS ARE MADEMINERALSTHERE ARE OVER 2000 MINERALS,BUT A DOZEN ARE COMMON.
Hard rocks are made of hard minerals.Softer rocks of soft minerals
Which rock strata is made of thehardest (most resistant to weathering)minerals? How do you know?
Which rock strata is made of thesoftest (least resistant to weathering)minerals? How do you know?
Most minerals are made of the sameelements: especially oxygen & silicon
THE DOZEN COMMON MINERALSARE CALLED: THE ROCK FORMERS.BECAUSE MOST OF EARTH’S ROCKSARE MADE FROM THEM.
MINERALS GET THEIR PHYSICALPROPERTIES FROM THE INTERNAL ATOMIC(CRYSTALLINE) ARRANGEMENT OF THEIRATOMS.EX: DIAMONDS AND GRAPHITE ARE PURE CARBONATOMS, BUT HAVE VERY DIFFERENT PROPERTIESBECAUSE THEIR CARBON ATOMS ARE ARRANGEDDIFFERNTLY.
MANY, MANY, MANY MINERALSARE USEFULL TO HUMANS BECAUSEOF THEIR UNIQUE PHYSICALPROPERTIES.SEE PAGE 15 OF YOUR EARTH SCIE CEREFERENCE TABLE.
SCIENTISTS IDENTIFY MINERALS THROUGHTHEIR PHYSICAL AND CHEMICALPROPERTIES.• COLOR• HARDNESS• STREAK• LUSTER• CLEAVAGE• SPECIAL PROPERTIES.
On the regents, I will usecleavage/fracture, luster, streak andhardness to identify one mineral.
COLOR• Some minerals can be identified by their colorex: sulfur is always yellow.• Color is NOT very useful because someminerals come in different colors. Ex: quartzcomes in 7 colors• Sometimes very different minerals have thesame color. Gold and pyrite are bright yellow.
Hardness: the ability of a mineralto resist being scratched.Hard minerals scratch soft minerals.
On the regents I will scratch my mineral ona glass plate….
If my mineral is harder than glass, it willscratch the glass plate….
If my mineral is softer than glass, it won’tscratch the glass plate….
Moh’s scale lists the hardness of someminerals
Moh’s scale is used to determine thehardness of unknown minerals
Streak: is the powder residue when amineral is rubbed on a bathroom tile
A mineral’s Streak is like a “finger print”. Itsstreak is always the SAME color.
On the regents I will see if my mineral leavescolored streak or non-colored (white ) streak
Cleavage and fracture: how mineralbreaks into pieces.
Cleavage: minerals breaks into smoothor flat pieces