2. Psalms 19:9-11
• The ordinances of the Lord are more
precious than gold, than much pure
gold.
• ….in keeping them there is great
reward.
3. • During the 1500s, someone discovered a large mineral
deposit in Borrowdale, England. People found they could
carve the mineral, graphite, into sticks and use them to
make dark marks on paper. The graphite was great for
writing, but easily broken. Early users wrapped the
graphite sticks in string to make them stronger. Years
later, people began inserting graphite sticks into hollow
wooden "cases," creating the modern pencil.
• Minerals are all around us—in our pencils, our
sidewalks, our homes, and even on our tables next to
the pepper (salt is a mineral). In this lesson, you will
learn about minerals.
4. What Are Minerals?
• Diamonds are minerals, but pearls are not. Salt
is a mineral, but not pepper. What makes a
mineral a mineral?
• The scientific definition of a mineral is a
naturally occurring inorganic solid that has a
definite chemical composition and a
characteristic crystalline structure.
• Minerals are inorganic, which means they form
from non-living materials.
5. Four basic questions asked to determine if a
substance is a mineral
• 1. Is the substance natural?
• Minerals must occur naturally. Humans
have invented hundreds of compounds,
and even several elements, in
laboratories. These materials are not
minerals because people create them,
rather than finding them in nature.
6. 2. Is the substance inorganic?
• Minerals must be inorganic. Substances
found only in living organisms are not
minerals.
• An inorganic substance
• - is a substance that is not made up of
living things or the remains of living things.
7. 3. Is the substance a crystalline solid at
temperatures near the Earth’s surface?
• Minerals must have a crystal structure.
• Minerals must be solid. The atoms in liquids
move more freely than in solids. Liquids are
unable to keep a crystal structure because of
this additional mobility.
• Crystalline solid-
• Solid whose particles are arranged in a regular,
repeating, three-dimensional pattern.
• The different crystalline structure accounts for
differences in their properties.
9. • Chemical Composition
• Have you ever helped someone cook a meal? Successful cooking
depends on a delicate balance among ingredients. It is important to
measure carefully. A recipe that calls for two cups of water and one
cup of milk won't taste the same with incorrect measurements.
• Minerals are like recipes. Their chemical composition is a balance of
different elements and compounds. Most minerals are made of an
exact amount of certain atoms. Hematite is a type of iron. It has two
atoms of iron (Fe) for every three atoms of oxygen (O). The
chemical formula for hematite is Fe2O3. If the number of atoms of
either element is changed, hematite doesn't form. For example,
having only one atom of iron and one of oxygen creates wustite
(FeO), an entirely different mineral.
10. 4. Does the substance have a definite
chemical composition?
• Chemical composition
• -is the relative abundance of the different
types of atoms in a substance.
• Minerals must have a homogeneous
structure. This means that a mineral will
always have the same ratio of elements. If
you cut a mineral into tiny pieces, each
piece will have the same chemical
composition. Quartz, for example, always
has one silicon atom for every two oxygen
atoms.
11. • Minerals can be elements or compounds
• Elements
• - consist of only one kind of atom
• Native minerals
• - minerals made of just one element e.g. gold,
silver, copper, and sulfur.
• Native metals like gold, silver, copper and
platinum, are much denser than water, and are
good conductors. They have bright metallic luster
and their colors are distinctive. Gold is bright
yellow, native copper has a dull red color, and
platinum is steel gray.
• Native minerals can also be a non metal like
diamond, carbon and sulfur.
12. • Compound
• - pure substance that consist of more than
one element e.g. fluorite – made up of
calcium and fluoride ions.
• Compound mineral
• -mineral made of a chemical compound.
Most compound minerals occur in
chemically similar forms that can be
grouped into mineral families.
13. Two Major Mineral Groups
• Scientists often categorize minerals by
their chemical composition. At the highest
level, minerals are divided into silicates
and non-silicates.
• 1. Silicate
• 2. Non-silicate
14. Silicate minerals
• Almost 25 % of all known minerals, and about 40% of the common
ores, belong to the silicate class. More than 90% of the earth’s crust
is made of silicates.
• Silicates contain
• both silicon (Si) and oxygen (O).
• Silicate minerals make up 96% of the Earth’s crust.
• Feldspar-
• -most common mineral in earth’s crust; white and pink grains in
granite rock
• Quartz-
• - second most common; is a pure silicate compound called silican;
six sided crystalline form, can be clear, rose, violet, smoky black;
clear grains in sand
• Micas-
• -soft, shiny minerals
• Talc-
• -softest known mineral: talcum powder
Quartz crystal
16. Categories of nonsilicate minerals
• Native elements-
• -made of 1 element e.g. gold, silver, copper, sulfur
• Carbonates –
• -contain carbonate, a compound made of carbon and
oxygen. Carbonates usually occur in marine
environments and caves. e.g. limestone in caves, shells
in oysters
• Halides-
• -inorganic minerals that contain combinations of fluorine,
chlorine, iodine, or bromine with sodium, potassium or
calcium
• E.g. halite, rock salt
• Used in fertilizers, photographic films
17. • Oxides-
• -Has oxygen and one other element
• e.g. oxide of oxygen and iron or
aluminum
• Oxide minerals are used to make
aircraft parts
18. • Sulfates-
• -Has oxygen and sulfur
• e.g. white sand in New Mexico, gypsum
• Used as plaster of Paris, toothpaste, paint,
cosmetics, fertilizers, paper, jewelry
19. • Sulfides
• - made of one or more metals and sulfur;
many are opaque; have characteristic
color, often have colored streaks.
Example: pyrite- fool’s gold( iron sulfide)
20. Let's Review!
• Minerals are naturally occurring elements or
chemical compounds with crystalline structures.
• Minerals must occur naturally, be inorganic, be a
solid, have a crystal structure, and have a
definite chemical composition.
• Minerals can be classified by their chemical
composition into silicates (which have silicon
and oxygen) and non-silicates (e.g., carbonates,
oxides, and sulfides).
