Rockin the Rockies

Rockin the Rockies
Rock Hounding

Friday, September 1, 2017

Pseudomorph Sunday Or A Return To Iron Hill

We found a lot of goethite ((FeO(OH)), pseudomorphs of goethite after siderite and even iron globs on smoky quartz crystals on a hill near Lake George so we've nicknamed the hill Iron Hill. I prospected around today for a while on Iron Hill and kept finding float crystals. There was nearly no slope near the top of the hill where I was prospecting and no discernible pegmatite yet every once and a while a 5 inch smoky or well formed amazonite would pop out of the dirt. I would dig down around the spot where I found the keeper but there would be no pegmatite even a foot below these occasional floater crystals. I kept prospecting for an hour or so but was not able to find the source of the float amazonite and smokies so I decided to show Bob, my digging partner, a couple of my float crystals and see if he was having any luck.  Bob was also finding some float amazonite along with a bit of goethite.  I told him I was going to quit digging in my area and try something else.  As I walked back to my old site to load up my tools I noted a 2 inch smoky basking in the sunshine. I marked that spot as my next prospecting site and returned there with my equipment. At least this spot had plenty of rock which suggested pegmatites somewhere near the surface rather than just all dirt. Three feet up the hill from where I found the float crystal there was a small pile of rocks that I supposed someone assembled. I noticed only a shallow depression from where these may have been dug but didn't believe whoever dug this dug very deep. As I began my dig I hit a number of smoky quartz shards about 10 inches down and thought just maybe I might be on to something. As I moved up the hill towards the pile of rocks I kept getting quartz shards and an occasional pseudomorph of goethite after siderite see: http://www.wasatchgemsociety.com/content/rock-talk-library/pseudomorphs  We’ve found plenty of pseudomorphs on Iron Hill before so these pseudomorphs came as no surprise, I picked a couple up and showed them to Bob who immediately recognized them for what they were. These pseudomorphs of goethite after siderite were bigger than what we had been finding so Bob decided to join in the fun and watch me dig. We were both concerned about the pile of rocks in front of me, but it looked to me like they were associated with a fairly shallow dig to my right and since I was finding quartz shards and pegmatite about a foot below the ground I continued my dig.  Soon the dirt began to turn orange-ish yellow and began to clump up.  Well it was obvious to me this clay signified the edge of a pocket so I put away my rock hammer and pulled out one of the wooden chop sticks John Wager had given us and began probing through the clay looking for crystals. Wager sticks work really well in clayish materials--everyone should have one. Or you can get some knock-offs from your local Chinese restaraunt. Wood is very soft and normally won't scratch crystals. While smoky quartz shards and a few crystals were fairly plentiful the highlight of this pocket was pseudomorphs of goethite after siderite.  Bob and I each got a nice fist sized plate of these pseudomorphs on matrix (pegmatite). Although these specimens are not highly prized by many I find them to be exceptional examples of pseudomorphs from the Pike Peak Batholith and very collectible. Yes, I would rather have some amazonite smoky combos but you take what you can get and this was better than getting shut out. By the way the previous digger who piled up a small rock cairn, put it right on top of the pocket I discovered.  Maybe I should just look for these rock cairns and pull out the crystals underneath ;-)  The sky was rumbling with thunder once again, my annoying headache had returned and I just unearthed a nest of large black ants that began crawling all over everything. I decided it was time to call it a day and return next week to finish up this pegmatite and check out a few rock piles on Iron Hill.  Hopefully the ubiquitous ants will have found a new home as well, until then happy rock hounding--Falls Coming!

1 comment:

  1. i love reading your blogs very interesting and informative, thank you.
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    ReplyDelete