ROCKS AND
MINERALS

MAIN IDEA…
EARTH’S MATERIALS INCLUDE ROCKS AND
MINERALS . THEY EXHIBIT CHARACTERISTICS
FEATURES AND HAVE ECONOMIC VALUE. EARTH’S
ROCKS UNDERGO TRANSFORMATION.
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PHILIPPINE MINERAL RESOURCES
The richness of the Philippines in terms of mineral
resources is being attributed to its location at the
western fringes of so called Pacific Ring of Fire – a
ground found to be super loaded with mineral
deposits. Globally, we are ranked 5th as most
mineralized country in the world. 3rd in
gold reserves, 4th in copper and 5th in nickel.
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EARTH’S
MATERIALS!
 ROCKS AND MINERALS
( THEY EXHIBIT
CHARACTERISTICS
FEATURES, HAVE ECONOMIC
VALUE, UNDERGO
TRANSFORMATION)
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THE ROCK CYCLE
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IGNEOUS ROCKS
 LATIN (IGNIS) – FIRE
 FORMED BY VOLCANIC ACTIVITY
 RECALL THE STRUCTURE AND CHARACTERISTICS
OF THE CORE AND MANTLE! MAGMA – IS
MOLTEN ROCK GENERATED BY PARTIAL MELTING
OF ROCKS IN EARTH’S MANTLE. IT CONSISTS
MAINLY OF SILICON AND OXYGEN, AND LESSER
AMOUNTS OF Al, Ca, Na, K, Mg, Fe.

IGNEOUS ROCKS
o MAY BE CHARACTERIZED BY THEIR TEXTURE AND
COMPOSITION
1. TEXTURE
 DESCRIBES THE OVERALL APPEARANCE OF THE
IGNEOUS ROCKS (SIZE, SHAPE AND ARRANGEMENT
OF INTERLOCKING CRYSTALS)
The rate of cooling influences the crystal size. Slow
cooling of magma results in the formation of large crystals.
On the other hand, rapid cooling results in the formation of
small crystals

IGNEOUS ROCKS
o MAY BE CHARACTERIZED BY THEIR TEXTURE AND
COMPOSITION
1. TEXTURE
A.COARSE-GRAINED – GRAINS CAN BE SEEN WITH BARE EYES
B.MEDIUM-GRAINED – GRAINS CAN ONLY BE SEEN THROUGH A
HAND LENS
C.FINE-GRAINED – GRAINS CAN ONLY BE SEEN THROUGH THE
MICROSCOPE

IGNEOUS ROCKS
o MAY BE CHARACTERIZED BY THEIR TEXTURE AND
COMPOSITION
2. COMPOSITION
 IS BASED ON THE CHEMICAL MAKEUP OF THE
PARENT MAGMA
They matbe divided according to light and dark
colored materials.

IGNEOUS ROCKS
o MAY BE CHARACTERIZED BY THEIR TEXTURE AND
COMPOSITION
2. COMPOSITION
A. LIGHT-COLORED
B. MEDIUM – COLORED
C. DARK-COLORED

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SEDIMENTARY ROCKS
 SEDIMENTS RESULT FROM THE UPLIFTING AND
WEATHERING → TRANSPORTED → DEPOSITED
IN DIFFERENT AREAS
Describes the breaking down or dissolving of rocks
and minerals on the surface of the Earth. Water, ice, acids,
salts, plants, animals, and changes in temperature are all
agents of weathering.

SEDIMENTARY ROCKS
 THE PROCESS BY WHICH THE SEDIMENTS ARE
TRANSFORMED INTO SOLID SEDIMENTARY
ROCKS IS CALLED LITHIFICATION!
A.COMPACTION
AS PILES OF SEDIMENTS ACCUMULATE THE MATERIALS BELOW ARE
COMPACTED → BY THE WEIGHT OF OVERLYING LAYERS → AS
GRAINS ARE PRESSED, PORE SPACE ARE GREATLY MINIMIZED →
REDUCING THE VOLUME
SHALE

SEDIMENTARY ROCKS
 THE PROCESS BY WHICH THE SEDIMENTS ARE
TRANSFORMED INTO SOLID SEDIMENTARY
ROCKS IS CALLED LITHIFICATION!
B. CEMENTATION
THE WATER THAT SEEPS THROUGH PORE SPACE BETWEEN
PARTICLES MAY CONTAIN CEMENTING MATERIALS → THROUGH
TIME → THE CEMENT SETTLES INTO THE SEDIMENT GRAINS →
FILLS THE OPEN SPACES → BINDS THE PARTICLES TOGETHER

“
”
SEDIMENTARY ROCKS ARE OF
PARTICULAR IMPORTANCE TO EARTH’S
HISTORY! FOSSILS ARE ONLY FOUND IN
SEDIMENTARY ROCKS!
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TYPES OF SEDIMENTARY ROCKS
• DETRIMENTAL SEDIMENTARY ROCKS (CLASTIC)
 THIS ROCKS COME FROM WEATHERED ROCKS SUCH AS IGNEOUS ROCKS
 THEY ARE COMPOSED OF ROCK FRAGMENTS THAT HAVE BEEN
WEATHERED FROM PRE-EXISTING ROCKS
• CHEMICAL SEDIMENTARY ROCKS
 THESE ROCKS COME FROM SOLUBLE MATERIALS PRODUCED LARGELY
BY CHEMICAL WEATHERING
 THE BASIS FOR GROUPING IS THEIR CHEMICAL COMPOSITION
 TYPE OF SEDIMENTARY ROCK THAT DO NOT DIRECTLY INVOLVED
MECHANICAL WEATHERING AND EROSION
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METAMORPHIC ROCKS
 CAME FROM PRE-EXISTING ROCKS CALLED PARENT ROCKS → MAY
UNDERGO CHANGES IN THE MINERALOGY, TEXTURE (GRAM-SIZE)
AND CHEMICAL COMPOSITION → BY THE ACTION OF HEAT PRESSURE
(STRESS) AND CHEMICAL AGENTS → THE TRANSFORMATION IS
CALLED METAMORPHISM!
 HEAT – IS THE MOST IMPORTANT AGENT OF METAMORPHISM
- IT MAY COME FROM MAGMA (RISING FROM BELOW)
• THE PARENT ROCK IS BAKED BY MAGMA (WHEN THE ROCKS FORMED AT
THE SURFACE OF EARTH ARE TRANSPLANTED TO GREATER DEPTH)
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METAMORPHIC ROCKS
 HEAT
CAUSES CHEMICAL REACTIONS → RESULTS IN
RECRYSTALLIZATION OF EXISTING MINERALS / FORMATION OF
NEW MINERALS
 PRESSURE / STRESS
Pᵒ INCREASES WITH DEPTH!
Pᵒ CAUSES THE SPACES BETWEEN MINERAL GRAINS IN THE
BURIED ROCKS TO CLOSE → PRODUCING A MORE COMPACT
ROCK WITH HIGHER DENSITY
AT GREATER DEPTH → MINERALS MAY RECRYSTALLIZE INTO
NEW MINEERALS → MAY DISPLAY MORE COMPACT
CRYSTALLIZED STRUCTURE
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METAMORPHIC ROCKS
 CHEMICALLY-ACTIVE FLUIDS
• INCLUDES WATER, CARBON DIOXIDE, AND OTHER VOLATILE
MATERIALS (ACT AS CATALYST TO PROMORE CRYSTALLIZATION)
• INCREASES THE RATE OF CHEMICAL REACTION
BY ENHANCING ION MIGRATION THAT MAY
CHANGE THE COMPOSITION OF ROCK
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MINERALS
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MINERALOGY
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 STUDY OF MINERALS
BUILDING BLOCKS
OF ROCKS

● MINERAL
 DEFINED AS NATURALLY FORMED,
GENERALLY INORGANIC, CRYSTALLINE
SOLID COMPOSED OF AN ORDERED ARRAY
OF ATOMS AND HAVING A SPECIFIC
CHEMICAL COMPOSITION.
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● MINERALS THEREFORE, CAN BE
DESCRIBED AS . . .
 INORGANIC - formed by natural geologic processes
 FORMED IN NATURE
 SOLID - crystalline substance that are solid at temperature
at Earth’s surface
 ATOMS HAVE THE SAME CRYSTALLINE PATTERN and
with SPECIFIC CHEMICAL COMPOSITION
 CRYSTALLINE ATOMS are arranged in an orderly
repetitive manner
 Can be represented by a CHEMICAL FORMULA
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● PHYSICAL PROPERTIES OF MINERALS
 LUSTER
 HARDNESS
 STREAK
 CLEAVAGE
 FRACTURE
 COLOR
 SPECIFIC GRAVITY
 CRYSTAL FORM
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LUSTER
● REFERS TO THE WAY OF LIGHT IS
REFLECTED FROM A MINERAL
SURFACE.
● SOME HAVE METALLIC SURFACE
SUCH AS GOLD, SILVER AND
COPPER.
● OTHERS ARE DESCRIBED AS
VITREOUS OR GLASSY, PEARLY,
SILKY, RESINOUS AND EARTHY OR
DULL.
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HARDNESS
● REFERS TO THE MINERALS
RESISTANCE TO BEING SCRATCHED.
● THE HARDER ONES ARE DIFFICULT TO
SCRATCH, THE SOFTER ONES ARE
LESS RESISTANT TO SCRATCHES
● FREDERICH MOH, A GERMAN
MINERALOGIST PREPARED A SCALE
OF HARDNESS WITH A NUMBER OF 1-10
IN THE INCREASING HARDNESS.
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COLOR AND STREAK
● REFERS TO THE COLOR
OF THE POWDERED
MINERAL
● THE SAMPLE IS RUBBED
ACROSS A PIECE OF
UNGLAZED PORCELAIN
OR STREAK PLATE.
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CLEAVAGE
● TENDENCY OF
MINERALS TO BREAK
ALONG PLANES OF
WEAK BONDING.
● DESCRIBED BY THE
NUMBER OF PLANES
EXHIBITED AND THE
ANGLES AT WHICH THEY
MEET
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FRACTURE
● MINERALS THAT DO NOT
EXHIBIT CLEAVAGE ARE
SAID TO FRACTURE
WHEN BROKEN.
● SOME BREAK LIKE
GLASS, SOME INTO
SPLINTERS OR FIBER.
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COLOR
● SOME ARE OF THE SAME
COLOR LIKE AZURITE IS
ALWAYS DEEP BLUE ,
MALACHITE IS GREEN,
CINNABAR IS RED AND
SULFUR IS YELLOW.
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SPECIFIC GRAVITY
● IS A NUMBER WHICH
REPRESENTS THE RATIO TO
THE WEIGHT OF AN EQUAL
VOLUME OF WATER.
● GALENA IS 7.5 TIMES HEAVIER
THAN A COMPARABLE
VOLUME OF WATER.
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CRYSTAL FORM
● EXTERNAL FEATURES
OF A MINERAL REFLECT
ITS ORDERLY INTERNAL
ARRANGEMENT OF
ATOMS
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CHEMICAL PROPERTIES OF
MINERALS
 A SAMPLE CHEMICAL TEST IS
A. TASTE TEST – NACL (COMMON TABLE SALT) HAS A
DISTINCTLY SALTY TASTE.
B. FIZZ TEST - CARBONATE MINERALS IN HYDROCHLORIC
ACID , GIVING OF BUBBLES OF CARBON DIOXIDE GAS.
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NATURAL RESOURCES
 THE EARTH’S CRUST AND OCEANS ARE THE
SOURCES OF A WIDE VARIETY OF USEFUL AND
ESSENTIAL MINERALS.
 RENEWABLE RESOURCES CAN BE REPLENISHED.
 NONRENEWABLE ARE SOME BASIC RESOURCES
SUCH AS IRON, ALUMINUM AND COPPER,
OTHERS ARE FUELS LIKE OIL, NATURAL GAS AND
COAL.

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NATURAL RESOURCES
 RICH DEPOSITS OF METALLIC MINERALS SUCH AS IRON,
NICKEL, COPPER, GOLD, SILVER, CHROMIUM, ZINC AND
LEAD ARE ALSO LOCATED.
 GOLD IS THE PRECIOUS METAL WHICH CAN BE FOUND
PURE IN NATURE.
 MERCURY RESERVES ARE LOCATED IN ALBAY AND
PALAWAN.
 OUR BIGGEST LEAD DEPOSITS ARE FOUND IN AYALA,
ZAMBOANGA.
 MOLYBDENUM DEPOSITS OCCUR IN BATANGAS

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CONSERVING OUR MINERAL
RESOURCES
 IT TOOK THOUSANDS OR EVEN MILLIONS OF YEARS TO
PRODUCE THESE RESOURCES.
 MINERAL RESOURCES ARE NON-RENEWABLE.
 IT IS IMPORTANT FOR US TO UTILIZE WISELY AND
CONSERVE OUR COUNTRY’S WEALTH FOR FUTURE
GENERATIONS TO COME.

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WE SHOULD:
 RECYCLE OUR PRODUCTS TO REDUCE WASTE
 RECOVER MINERALS FROM MINE TAILINGS
 CONTROL CORROSION
 USE ALLOYS WHENEVER FEASIBLE

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“ WE CAN HELP
CONSERVE OUR
RESOURCES FOR
OUR NEEDS
DURING OUR
LIFETIME. “