Cochise
College Student Papers in Geology
Geology Home Page physical
geology historical
geology planetary
gems
Roger Weller,
geology instructor
wellerr@cochise.edu
Diamonds
Melanie Lewis
Physical
Geology
Spring 2005
Learning about Diamonds
Every woman in the world is in love
with diamonds, as am I. From early childhood
on, when I saw my mother putting on her diamond jewelry, I knew that, when I
grew up, I would have my own collection of diamonds to show off. Today, I am beginning to start my collection. At only nineteen, I have a dozen pieces of
diamond jewelry to wear and enjoy.
Loving diamonds so much, I decided to learn more about them in order to
appreciate them even more.
I have always known that diamonds
are found in the earth by mining, but I never knew all the details. It turns out that diamonds are transported to
the earth’s surface by molten rock, or magma, that originates at great depths
within the earth. This magma, which is
carrying diamonds and other materials and forms the earth’s mantle, rises and
erupts into volcanoes. Underneath those
volcanoes is a carrot shaped “pipe” filled with volcanic rock, mantle
fragments, and embedded diamonds. The
rock in which the diamond is embedded is called kimberlitic, after the city of
It is interesting to find out what
exactly the diamonds that I am wearing are made out of. During my research I learned that diamond is
carbon in its most concentrated form, and except for trace impurities like boron
and nitrogen, diamond is composed entirely of carbon, which is the chemical
that is fundamental to all life.
Many people have the misconception
that diamonds only come as colorless stones.
In reality, diamonds come in many different colors. A diamond can be almost any color in the rainbow. Colored diamonds are often referred to as
“fancies” (Nature). The colorless
diamond is a chemically-pure crystal, but by adding nitrogen, a yellow diamond
can appear, and by adding boron, a blue diamond can appear. Many other colors such as red, violet, real
white, and black are possible colors for diamonds (American). Today, people are moving away from the
classic clear diamond and moving towards more color, although the colorless
diamond will always stay very popular.
Diamonds are known for their hardness, which is the
measure of a substance’s resistance to being scratched. The diamond is the hardest substance known to
man, and only a diamond can scratch another diamond (American). Because diamonds can withstand such extremely
high temperatures and corrosive conditions, they are ideal for use as windows
in industry and in space probes. Diamond
is also used for scalpels, and it is very effective because of its sharp, hard
edges that never dull, and also because diamond’s hydrophobic surface ensures
that wet tissue does not adhere to the blade (Nature). On Mohs scale of hardness, diamond is ranked
the hardest material, because it can scratch other materials with a lower
ranking.
Diamond is not fragile or even prone
to breaking, but all substances can fracture or shatter. Because of its particular crystal structure,
diamond has certain planes of weakness along which it can be split. It is said that diamond has perfect cleavage
in four different directions, meaning that it will separate neatly along those
lines instead of becoming jagged or irregular.
Diamond is also very dense given the low atomic weight of carbon
(American).
One of the things that draws women
to diamonds, is that unbelievable shine and luster that they give off. Every woman enjoys the feeling of being the
center of attention when she walks into the room with a gleaming stone on her
finger. Diamond has a great ability to
refract light, which means to bend or slow down light, as it passes through
it. Diamond also displays the maximum
amount of reflectance for a transparent substance, displaying what is called an
“adamantine” luster. Diamond also has an
unusual property for a mineral, which is that it can repel water. Diamond’s strong bonding and carbon
composition cause its surface to repel water, but readily accept wax and
grease. Those two properties provide an
effective means of separating diamonds from other minerals that come out of
mining operations. Washed gravel
containing diamonds is flushed with water over a sloping surface covered with a
mixture of wax and grease. The diamonds
stick to the table, while the wetted waste minerals wash away over it. Diamonds readily pick up a greasy film, as
can be seen on one’s jewelry, but cleaning them with ammonia or a good detergent
restores their brilliance (American).
I never knew exactly how many places
in the world mined diamonds until I learned that today diamonds are mined in
about 25 countries, on every continent except Europe and Antarctica, including
major producers from several South African countries, Siberian Russia, and
Australia. Only a few diamond deposits
were known until the 20th century.
For 1000 years starting in the 4th century,
Today diamond symbolizes wealth,
durability, status, and peerless quality.
Across time and cultures diamond has also been associated with
invulnerability, lightning, magic, healing, protection, and poisoning (American). To me diamonds symbolize timeless grace and
beauty that will never fade away.
Diamonds have shown up as many forms of jewelry from earrings to
necklaces. But the most prominent piece
of diamond jewelry is the ring. May it
be an engagement ring, a wedding ring, or an anniversary ring, one or more
diamonds are always present. But in
ancient times diamonds were not used as jewelry, and instead they were used for
such purposes as engraving other gems like sapphire, and for drilling holes
into headstone beads (Nature). Today we
are taking diamond use back towards the ancient times with eighty percent of
the diamonds mined annually being used in industry. Diamond has three primary roles in
industry: it can be used as a cutting
tool, it can be imbedded in another material and used as a tool or an abrasive,
and it can be turned into powder or paste for grinding and polishing
(American). An interesting discovery for
me was when I learned that every copper wire in my computer, television, and
house had been shaped with a die, the device that squeezes wire to the desired
diameter, made from diamond (Nature).
Diamond is selected in the industry for such use where its hardness and
resistance to abrasion, its long working life, and fast cutting action outweigh
its cost (American).
To me diamonds will always be the
most beautiful and valuable things that I own.
It has been fascinating to learn more about my favorite gemstone. I never knew about many of the things like
mining and industrial use until I researched.
It is really fun to know that diamond is so much more than just a stone
that sits in a ring and looks nice, but actually does a variety of useful
things.
Works
Cited
The Nature of Diamonds: Facts About
Diamonds.
http://www.sdnhm.org/exhibits/diamonds/facts.html