Rockin the Rockies

Rockin the Rockies
Stowe Mtn

Wednesday, December 21, 2011

Petrified wood and Tumbling

Refer back to 03/04/2011 "An adventure to the Denver Basin looking for petrified wood."  In the winter I clean, examine and tumble specimens found over the warmer months. I finally got around to tumbling some of the petrified wood I collected last March and if I may say so I think they look pretty good.  My friend helped me build a tumbler for about $50 (Bearings, used motor,scrap wood and belts).  While I've read some people use old paint cans and other barrels to use as tumbling barrels, I decided to buy a rubber barrel (another $50). No sense in doing all the work of collecting, storing and polishing only to have a crummy barrel mess everything up.  Anyway here is a picture of some wood that went through 4 of the 5 tumbling stages.  A burnishing step with soap flakes is described as a finishing step, but I'm not sure I need to.  Stones look fine as they are.
Red, Yellow, Black and White all good looking stones

Friday, December 2, 2011

St Peters Dome and Rare Earths - - Astrophyllite

Topo map of St Peter Dome area
There is plenty of massive fluorite, but not very gemmy.  Does polish well though.

Now that the ground is frozen it's time to reflect on some prior rock hounding trips.  One of my favorite sites to visit is St Peters Dome, a rather large foothill of Pikes Peak, just west of Colorado Springs.  The best way to get there is take Old Stage Rd west from the Broadmoor area and follow it until it intersects with Gold Camp Rd (4-wheel drive recommended but not necessary when the roads are dry).  Gold Camp Rd is closed to vehicles. There is an occasional dirt bike rider or ATV, but the road is fairly wide and safe for walking. I have collected primarily on the eastern and northern slopes of St Peters Dome with mixed results.  However, every time I've rock hounded there I've found something. Usually some quartz points or fluorite.  You can find massive fluorite just past the shooting range on the south side.  I believe the shooting range has been closed for quite some time and you shouldn't have any trouble with that.  Occasionally a chain crosses the road to the site, but it's only a 1/4 mile hike from the St Peters Dome trailhead.  The fluorite does polish well, and may tumble as well, though I have not tried that.  The color is purple and green (see pic).  You'll need some gads or chisels and a rock hammer to free up a nice piece.  The hike around St Peters Dome on Gold Camp Rd is all downhill, so just remember to leave yourself plenty of time and energy/water to get back.  I've found that the further you stray from the road the more likely you are to find something interesting. At this time I don't believe there are any claims around St Peters Dome, but you should probably check before digging.
St Peters Dome is known for many rare earths.  One day I dug into an interesting looking area on the northern flank of St Peters Dome and found some astrophyllite (see pic).  I wasn't sure what it was til I checked with the local rock shop and rock club.  Fairly rare I guess and primarily found in Russia. The easiest but longest way around St Peters Dome is to follow Gold Camp Rd.  I have cut across the area near the St Peters Dome trail head (see topo map) on the way down, but usually follow the road back up.  Hiking this area is enjoyable too, just keep an eye on the weather.  One person was killed a couple of years ago by lightning near the shooting range.  I've also seen bear scat around.

You can see the needle like structure of the Astrophyllite and bow-tie appearance.
Astrophyllite: (K,Na)3(Fe++,Mn)7Ti2Si8O24(O,OH)7   YIKES!!!