Download minerals intro key - hrsbstaff.ednet.ns.ca

Geology 12: Minerals Introduction (Key)
Diamonds are minerals that are valued for their durability, beauty, and rarity. They form deep
in the earth under conditions of extreme heat and pressure, and are brought to the surface of
the earth by the forces of volcanism and weathering. Generally, diamonds - and the rocks
they’re found in - are very old. Studying diamonds, therefore, can help scientists reconstruct
the processes that were central to the formation of the earth itself.
The physical properties of a diamond are determined more by the crystal structure of the
diamond than by its composition - consider that diamond and graphite, despite their vastly
different physical properties, are both composed of pure carbon. Every mineral is
characterized a particular type of crystalline structure that is largely responsible for its
physical properties.
Video clip #1:
http://www.teachersdomain.org/asset/nat08_vid_aging/

How do diamonds get to the surface of the earth?
Carried by special high-speed volcanoes.

Why are diamonds valuable to scientists?
They tell us about the processes happening beneath earth’s crust.

How do scientists determine the age of rocks and minerals? Why is it that “a diamond
never grows old”?
They generally use radioactivity (radiometric dating). All other minerals contain
radioactive materials that, over time, decay at a known rate. But a diamond’s structure
is so stable that it does not decay.
Video clip #2:
http://www.teachersdomain.org/asset/nat08_vid_formation/

What materials and conditions are essential to the formation of a diamond?
Carbon must be exposed to the right conditions: deep within the earth’s interior, the
correct temperature and pressure to support the unique bonding of the carbon atoms.

How do you think artificial diamonds might be manufactured? What engineering
problems might be involved in doing so?
Achieving the high temperatures and pressures necessary would be very difficult. Besides, if it
was easy to make diamonds, they wouldn’t be valuable anymore!