What is a Mineral?
A mineral is a naturally occurring, inorganic solid, with a
definite chemical composition and an ordered atomic
arrangement. This is kind of hard to understand but if you
break it down it becomes very understandable.
Minerals are naturally occurring, they can not have been
made by humans.
Minerals are inorganic, meaning they could never have
been alive and are not made up of living tissues like plants or
animals.
Minerals are naturally occurring solids, not liquids (like
water), or gases (like the Oxygen or Carbon Dioxide)
Although snow, sleet and ice are minerals. (remember
naturally occurring) Ice cubes do not qualify!
Minerals have a definite chemical composition, each
mineral is made of a particular chemical element or group of
chemical elements.
Minerals have an ordered atomic arrangement, The
elements that make up any mineral are arranged in a
particular way - this is why minerals 'grow' as crystals. Like
elements naturally want to group together in a crystal
structure that is unique to that mineral.
All the Elements that make up every mineral can be found
on the Periodic Table
What is a Fossil?
The word Fossil comes from the Latin word Fossilis
meaning Dug up. There are two types of fossils, Body
Fossils are the physical remains of living things that have
been naturally preserved. In most cases only the hard parts
of the animal like teeth, bones and shells become fossilized.
There are instances where feathers skin and fur have also
been found. The body parts become buried by sediments
and absorb minerals and Carbon and become stone.
The other type of fossil is a Trace Fossil. A Trace fossil is
the physical evidence that a living thing had once been
there. These include foot prints, tail drags, insect trails,
leaf impressions, invertebrate burrows and feces.
Sedimentary Structures
Any visible feature made by natural occurrences is
considered a Sedimentary Structure. These visible
features within Sedimentary Rocks that formed at the time
they were deposited and are a geological record of that
moment in time. The most commonly observed
sedimentary structure is stratification. This is the process
by which layers of sediment are built up over time and
through Geological Process of heat and pressure become
Sedimentary Rock. Things like, Sand ripples, mud cracks,
rain drop impressions and salt crystal casts are all
Sedimentary Structures that can be found in these layers.
They provide information about specific processes that
occurred while that particular layer of sediment was being
deposited and can be very useful in determining
environmental conditions. These structures are often
mistaken as fossils but they are not.
What is a Rock ?
Most rocks are made of minerals. However, all rocks are not
the same. That is why rock Geology is so interesting and fun.
Every rock has its own story.
Some Rocks are made of one Mineral like Quartz and others
like Granite are made of three Minerals (Mica, Quartz and
Feldspar)
Rocks can be put into three basic rock types
igneous, metamorphic and sedimentary,. How a rock is
formed determines which group it is placed in.
Igneous rock is one of the three main rock types rockscoming from the Latin word (Ignis) meaning fire.
There are 2 types of Igneous rocks
Intrusive Igneous rock is formed through the melting, cooling
and solidification of Magma. Molten Rock below the surface of
the earths crust is called Magma. GRANITE is an Intrusive
Igneous Rock that is made of 3 different minerals, (Mica,
Quartz and Feldspar)
Extrusive Igneous Rock is the same melted rock (Magma)
but when it gets pushed out on top of the earths crust and hits
the open air it then becomes Lava. Basalt also called Trap
rock is a prime example of an Extrusive Igneous Rock.
The 2 main things that act on these 2 forms of Igneous rock to
have it form such different types of rock is air and water.
Metamorphic Rock
Metamorphic comes from Greek words meaning "change" and
"form".
Heat and pressure can change many things. They can even
change rocks. The name for rocks that have been changed by
heat and pressure is metamorphic
Metamorphic rocks form deep in the earth where high
temperature, great pressure, and chemical reactions cause one
type of rock to change into another type of rock.
Metamorphic rock can be any of the 3 basic rock types.
These rock types can be affected or changed by the violence of
Plate Tectonics which causes very high temps and pressure. A
rise in Magma from deep in the earth can cause conditions where
Metamorphism can occure.
Some examples of rocks changing
Sandstone becomes Quartzite
Shale becomes Slate
Limestone becomes Marble
Sedimentary Rock
Is rock formed from particles, called sediment, that are worn
off other rocks by wind and water erosion. The particles are
sand, silt, and clay that wash into valleys from surrounding
hills. Sand has the largest particles while clay has the smallest.
If there are a lot of pebbles mixed with the sand, it is called
gravel. The sediment gets turned into rock by being buried and
compacted by pressure from the weight above it. Another way
it becomes rock is from being cemented together by material
that has been dissolved in water. Often, both cementing and
compaction take place together.
***Does any body know what rock is not a mineral?***
The only Rock that is NOT a Mineral is COAL. Coal is a
Sedimentary Rock made by decaying Organic material.