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Objectives
• Native Elements
• Oxides
• Hydroxides
• Halides
• Carbonates
• Sulfates
• Phosphates
(Mg,Fe)O, a possible phase in Earth’s mantle
FeO, a possible component of Earth’s core
0
FP
Ca-PV
Mg,Fe,Al-PV
80 95 100%
Dzeiwonski & Anderson 1981
Fei & Bertka 1999
Life on Mars?
hematite
&
olivine
Goethite - Fe(OH)3
Quic kTime™ and a
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Johann Wolfgang Goethe, 1749-1832
A German polymath: poet, novelist, scientist, painter, etc.
The Sorrows of Young Werther
Gibbsite - Al(OH)3
George Gibbs, 1776-1833
An American mineralogist, who donated a collection of 12,000
specimens to Yale University
Carbonate minerals are useful
• Carbonates cover 7% land surface
• Greater than 50% oil and gas
reservoirs worldwide are contained
in carbonate rocks
• Major economic importance as
industrial "mineral" (agriculture
stone, cement)
Carbonates are born, not made
Coral reef
Stromatolites
living fossils
Pacific reef
Red Sea reef
Florida reef
Caribbean reef
Carbonate cavern
Stalactites & Stalagmites, NM, USA
Sinkholes
Winter Park,
Florida
Sinkholes, FL, USA
Karst terrain
Guilin, China
Munching microbes could cleanse arsenic-contaminated
groundwater Sulfate-reducing bacteria will consume sulfate and reduce
it into sulfide. The sulfide then reacts to precipitate arsenic, leaving little in
solution.
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2005
U. of I. finds solution to arsenic in wells
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When the scientists analyzed water from 21 wells, all fed by the Mahomet
aquifer in central Illinois, they noticed that the more sulfate they found, the
less arsenic there was.
Well-water bacteria that are harmless to humans but death on arsenic were
responsible, said geology professor Craig Bethke, an author of a paper to be
published next month in the journal Geology. "They breathe in sulfate and
breathe out sulfide," he said. The sulfide reacts with arsenic, causing it to
settle out and never reach the surface.
Just add salts
That suggests owners of wells with unhealthy levels of arsenic can simply
add sulfate, Bethke said. Sulfate salts are inexpensive, readily soluble and
easy to find.
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Nita Sahai
How do our bones and teeth grow?
The earliest mineral formed in bone growth is in the
nanometer size-range. Previous studies were unable to
identify the phase because they relied on traditional
methods like X-Ray Diffraction which work best in the
micrometer size-range. Identifying the earliest mineral
phase that eventually becomes bone (apatite) can help
in the development of treatments for osteoporosis and
other bone-diseases. Determining the mechanism for
heterogeneous apatite precipitation also has
environmental applications in remediation of pollutant
phosphate.