August 2009 Archives


Comstock Mine Dumps
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Amanda picks through the rocks at the base of the mine dump.
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On the last day of a camping and rockhounding trip through Northern Arizona and Southern Utah, we visited a mine dump west of Cedar City, Utah. The rock piles were immense and forbidding. But there was much to be found. The material contained a great deal of magnetite as we later discovered its effect on a compass needle. I still haven't identified a number of the clear, cream, yellow and orange crystals that adorned the stones we brought back. Several specimens turned out to be fluorescent, glowing orange, yellow and white under long wave UV. This is definitely an area I would like to pick through again.


Collection of rocks I collected at the site.
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Collection SiteComstock Mine Dumps, Iron County, Utah, USA
37:36.874 N 113:23.576 W
DateJune 21, 2009
Minerals CollectedCalcite, Dendrites, Magnetite, ++


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This stone is only mildly magnetic, giving just the slightest tug on a compass needle. Rust colored and clear crystal runs through it. The outer structure of the orange mineral is best seen in the enlarged image. A very small, turquoise colored fleck can be seen in the center of the wide image. I'm not sure if this is contamination from another stone in the rock dump or if it is native to this specimen, but we collected no other material of that color. It is yet another piece in need of testing to try and narrow down the species.

One possibility I'll look into is whether the orange/brown material is Limonite after Pyrite. The external brown form has emerging crystal forms that appear to be cubic amid striated, botryoidal features.


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Mineral TypeMagnetite - Fe+2Fe+32O4
Unidentified Minerals
Size7.5 x 4.5 x 3 cm
Collection ID09062107J
Collection LocationNear Comstock Mine, Iron Springs County, Utah, USA
37:36.874 N 113:23.576 W
Collection DateJune 21, 2009

Lightning - AUG 5 & 12, 2009

We've enjoyed some evening lightning lately--the best kind of fireworks.

This first shot was from Edmond, Oklahoma on August 5, 2009. While sitting outside, we watched as a line of anxious cumulus to the north finally pushed their way through the cap and sprouted a healthy storm. The frequent and constant lightning illuminated the crisp, sculpted edges of the cloud and occasionally revealed bright stitching as warped streamers fell from the sides.


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SubjectCumulonimbus and Lightning
LocationEdmond, Oklahoma, USA
DateAUG 05, 2009; 10:07 PM CDT
EquipmentCanon EOS 300D + Kit Lens
Settings30 sec, f/9.0, 18.0 mm, ISO 800
ProcessingNoise reduction, power line removal, contrast & color management in Photoshop CS3

This next shot was taken from home earlier this evening as a storm was pushed north by a line of convection along the Mogollon Rim. Flagstaff doesn't often see evening lightning displays since the storms fire up earlier in the day before racing off to the lower elevations leaving more stable air behind for the rest of the night. That wasn't the case tonight and we saw some brilliant webs of light igniting the sky to the south.


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SubjectLightning
LocationFlagstaff, Arizona, USA
DateAUG 12, 2009; 08:26 PM MST
EquipmentCanon EOS 300D + Kit Lens
Settings30 sec, f/9.0, 18.0 mm, ISO 200
ProcessingNoise reduction, contrast & color management in Photoshop CS3