Many people remember the Horner Museum's display of
fluorescent rocks. These rocks are
currently on display in the Benton County Museum in Philomath and will probably be moved
to the new museum in downtown Corvallis.
Recently, Exhibitions Curator Mark Tolonen asked me to check a list of
other rocks to see if they fluoresced. All the Horner Museum's rocks are still
packed as there were for the move -- wrapped in tissue paper in boxes with many
other rocks. So finding any one item is
a tedious process of unwrapping, checking the identification number and
re-wrapping. In addition to the ones
Mark asked me to find, I discovered some other specimens which I found visually
interesting.
One was a slice of silicified bone.
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| Silicified bone |
You've probably heard of petrified wood. A similar process produced this sample. A bone became buried in the sediments from a
flood or river or under volcanic ash.
Ground water containing silica entered the bone, broke down the cell
walls and left silica in the empty space. Time and pressure turned the silica
to stone.
I also liked the patterns in these two samples of wardite
from Utah.
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| Wardite |
Chemically wardite is hydrous sodium aluminum phosphate
hydroxide. Named for scientist Henry Augustus Ward, it is famous for its
unusual crystal structure. It is often
found mixed with two other phosphate minerals, variscite and crandallite. The former greenish in color, ranging from
yellow-green to blue-green, while the latter creates white veins. Apparently,
these minerals often combine to create these patterns that remind me of images
of the brain!
By
Martha Fraundorf, Volunteer for Benton County Historical Society, Philomath,
Oregon
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