Native Elements

1
Objectives
Native Elements Oxides Hydroxides
Halides Carbonates Sulfates Phosphates
2
(Mg,Fe)O, a possible phase in Earths mantleFeO,
a possible component of Earths core
Dzeiwonski Anderson 1981 Fei Bertka 1999
3
Life on Mars?
hematite olivine
4
Goethite - Fe(OH)3
Johann Wolfgang Goethe, 1749-1832
A German polymath poet, novelist, scientist,
painter, etc.
The Sorrows of Young Werther
5
Gibbsite - Al(OH)3
George Gibbs, 1776-1833
An American mineralogist, who donated a
collection of 12,000 specimens to Yale University
6
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)

7
Carbonates are born, not made
Stromatolites living fossils
Coral reef

8
Pacific reef
9
Red Sea reef
10
Florida reef
11
Caribbean reef
12
Carbonate cavern
Stalactites Stalagmites, NM, USA
13
Sinkholes
Winter Park, Florida

• Sinkholes, FL, USA

14
Karst terrain
Guilin, China
15
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.
2005
16
U. of I. finds solution to arsenic in wells
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.
17
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.