Sand, Big Talbot Island, Florida
The bright white grains and those with numerous bands of pale colors tend to be zircons in this image. The roundish
grain near the center is one example and the bipyramidial grain to its right is another. Both are zircons. The orange grains are rutile. The black
grains are magnetite. The heavier minerals in the sand are easily separated from the dominant quartz by sieving the sand through a US #170 sieve
(90 micrometer). The dense minerals; garnet, rutile, zircon, magnetite, etc, pass through the sieve and the quartz is retain.
Transmitted Circular Polarized Light
Significance in the Environment:
This is an example of density classification by size in beach sands.
Greenberg, Gary, A GRAIN OF SAND: NATURE'S SECRET WONDER, Voyageur Press, 2008.
Welland, Michael, SAND: THE NEVER ENDING STORY, University of California Press, 2009.
(Good Information on the microscopy of sand, Great site for more information on microscopy in general)
(Good Information on Sand with links to more information on sand)
(Brief, very informative video on what can be learned from the shape of a sand grain.)