Smoky Quartz at Lake George

Normally I go rock hounding 2-3 times a week. The past two weeks I have only gone once a week due do to other commitments. Last week I found a small but productive pegmatite towards the end of the day with many small smoky quartz crystals. Seeing as it was the end of the day and I had a HS graduation party to go to I buried the pegmatite. I had not been able to get back until yesterday and probably won't go again this week due to my rock club (CSMS) having its rock and mineral fair this weekend. At the fair, I will display petrified wood and my digging friend will show off his Lake George finds. I think people will be surprised at the quality of the crystals Bob will display, but that is for another entry.
I dug out the pegmatite yesterday and once again found many small smoky quartz crystals. Most of the crystals were less than 1" in length. The crystals were very gemmy, but never attained any length or girth. I was somewhat puzzled by the availability of pegmatite quartz and lack of any larger crystals. The pegmatite was also very close to the surface. After digging out the pocket I decided to dig below the pocket (down the hill) and work up to the pocket. Hoping to catch some float crystals. This paid off. Despite the slope being very shallow (maybe 5 degrees) there were float crystals that were better than anything I found in the pocket. Hoping that there was another pegmatite that I might have missed between the float and my pocket up the hill, I continued to dig up the hill and work down every time I found a crystal. Unfortunately it appears the float did come from the original pocket. Still I was glad I had taken the time to go down the hill and work up to the pocket finding some nice gemmy 2" float crystals with very nice terminations. Often float crystals are more damaged than crystals you find in pegmatite pockets, but this was not the case with the float I found.
As the day winded down, I took some time to prospect the area more and almost immediately found smokys. These crystals were also small and hooded (see example below). I also found a nice piece of amazonite on my hike out. I'll have to prospect that area as well. Much to do at this site, may keep Bob and myself busy all summer... stay tuned.

Float Crystal 2" Chisel Point

Float Crystal Drill Bit Point

Odd Hooded Crystal

Field Trip for Tourmaline

Tourmaline in the Rockies can be found, but is often not the real gemmy crystals that people make jewelry out of or sell for big money. As a crystal collector I find the form and luster of tourmaline/schorl desirable NaFe²⁺₃Al₆(BO₃)₃Si₆O₁₈(OH)₄

We had an old time crystal hunter rejoin our crystal club. He brought in a number of well formed and terminated schorl crystals. They ranged from pencil to thumbsize in thickness and a couple crystals exceeded 3 inches. Well, we got excited about that and so he helped lead a field trip to the site. When we got to the spot near Badger Mtn, he said he hadn't been there since the early 70s and had dug out most of the schorl. Oops, would have been nice to know this ahead of time. Anyway, we gave it a shot. Soon we found garnets. The garnets were fairly small and not gemmy, they were surrounded by mica and resided in the host quartzy pegmatite. Perhaps the garnets are almandine garnets Fe₃Al₂(SiO₄)_3, the color was brownish. I will have to look into that more. Upon careful inspection of the garnets, I noticed that there were small schorl crystals intermixed with the garnets (see picture below). Our leader mentioned that the best schorl could be found in quartz chunks. Evidently when these quartz chunks are put in a freezer the schorl will sometimes pop out. Schorl must contract more than quartz. Our leader said that schorl could also be found within feldspar, but is nearly impossible to extract without breaking the crystals. Seems to me a few pieces of nice tourmaline sticking out of the host rock is just as appealing as single tourmalines frozen out of the quartz... and so the hunt was on. My nephew Andrew won the prize and found a perfectly terminated pencil thick 2 inch long tourmaline (float). I found garnets and tourmaline shards. Perhaps tourmaline does not get along well with my crack hammer (kidding). My rockhounding friend Bob, found a broken but well terminated tourmaline. While the trip was not well attended everyone went away with something collectible. I think some more prospecting in the area might turn up a better spot that has not already been prospected quite so much. Until then its back to Lake George for smoky quartz and amazonite!

Looking for float or debris late in the day... somewhat relaxing pose

Andy and I watching my nephew pull out tourmaline pieces

Fragmented tourmaline resting over garnet on matrix

Dime-size garnet

One of Bob's tourmaline finds

Crystals in Miarolitic Cavities of Lake George Pegmatites

My rock hounding friend and I have returned to Lake George in search of crystals. We've had a slow start to the 2013 season because of the cold and snow we've had this spring. So far we haven't had much success, but perseverance and observation are key to finding the miarolitic cavities that contain the much sought after crystals. The miarolitic cavities or vugs is where the heated mineral enriched liquid cavities within the Lake George pegmatites produce crystals. As the pegmatites and cavities cooled over 1 billion years ago the crystals formed in the solidifying pockets. As the pockets contiued to cool they crack and end the crystal forming process. Due to weathering and other erosion processes many of these now collapsed crystal pockets are near the earth's surface and ready for harvesting. The difficulty in finding the collapsed pockets stems from hundreds of people digging through the pegmatites and finding the easy to get crystals. Sometimes a portion of the pegmatite is exposed to the surface and creates "float" crystals. The crystals are called float because they are on the surface and detached from their source. Inexperienced rock hounds often pick up these float crystals or keys to the location of the crystal pocket without realizing they've not only missed the mother lode, but also erased evidence for others to find the crystal pocket. One prospector at Lake George uses track hoes to dig down over 20 feet into the earth's crust to discover and follow pegmatites opening up crystal vugs. So far this year I have found 4 collapsed vugs with crystals, all within 1-3 feet of the surface. Unfortunately the pockets were small and many of the crystals were either broken or had quartz overgrowth. The breakage can be a result of either the original pocket rupturing under pressure during crystal formation, or the grinding of crystals against each other over millions of years of frost thaw cycles and other erosion processes. I believe the overgrowth of quartz over the smoky crystals is a result of a later infusion of quartz into the vug. This quartz covers the smoky crystals to varying degrees and if not gemmy, hoods the smoky crystals making them somewhat unsightly and not very desirable.  If the hooding quartz is smoky or clear, the crystals are more desirable and are described as phantom smoky crystals as the original smoky is visible through the later quartz hooding. These hooded crystals are highly prized.

This smoky cluster has a lot of overgrowth and is rather unsightly. Too bad the bluish fluorite (lower left) was not larger

A nicer crystal grouping found on Monday... no quartz overgrowth (crystals 1.5-2 inches)

Vug Clay at Lake George

Another day rockhounding at Lake George and another pocket of crystals. This is one of the first times I've run into blackish purple greasy clay in a crystal pocket.  Most often the clay is either reddish (iron-stained) or yellow. I've also run into grayish material. The particular pocket I was in this day had blackish purple clay and the crystals were not very collectible due to breakage and additional quartz overgrowth. I like clear quartz over smokys which gives the illusion of phantoms or ghost smoky crystals, but not the granular/rough opaque quartz overgrowth on smokys. We sometimes say the smokys are hooded when this happens. I got into a discussion with my digging buddy Bob regarding colors of clay and if that has any correlation to the quality of crystals found in the clay.  We both have had very good luck with red clay and poor luck (crystal quality) with blackish purple clay. I'm afraid our sample size is not sufficient to make any conclusions. Anecdotally crystals found in the yellowish clay are harder to clean and the smokys don't seem to have the same lustrous exterior as those found in the red clay.  This got me to thinking is the clay in the pocket from the surrounding material or is the clay a result of the soup left in the miarolitic pocket after crystal formation. Since every pocket I've ever found has been broken imploded/exploded I'm guessing it's a mixture of leftover vug material and surrounding decayed/weathered pegmatite.  I decided to do a search on the internet and not only was there a discussion about clays in miarolitic cavities but it concentrated on the Pikes Peak Batholith see Mineralogy and Provenance of clays in Miarolitic Cavities of the Pikes Peak Batholith, Colorado. by Kile.  While this article was a little above my head scientifically speaking, it seems part of my hypothesis is correct, that the clay is from both the leftover vug material and surrounding weathered pegmatite. The article mentioned the clay varieties smectite, Illite and kaolinite being predominant in the vugs (never knew there was so much to know about clay). The author also mentioned infusion of material from hydrothermal processes after the pockets form. I think some of the fluorites are formed that way. My bigger question was unanswered, does the color of the clay in a pocket have any correlation to the quality of the crystals therein. Does the color of the clay indicate a higher concentration of elements inhibiting crystal formation or luster? Enough investigation for one day. Here are some pictures of the latest dig....

Checking out the latest crystals

A pretty gemmy crystal



Darker area is pocket with broken quartz crystals

Restaking a claim & late snow at Lake George

A friend of ours has a few claims north of Lake George and he has been sick for awhile. He asked us if we would be willing to restake his claim this year(what are friends for?). Well this turned out to be more work than we thought. Thank god for GPS. We found the first claim marker quite easily, but converting between coordinate systems and searching for vandalized posts was not what we expected. We got two claims restaked, but the weather set us back so that we will have to try again next week. We set out to restake the second set of claims only to be turned back by the weather. We thought there would be snow on the claim but didn't realize the depth and extent of the last snowstorm up in the mountains. Often a snowstorm will hit the front range mountains of Colorado and leave interior mountain areas like Lake George high and dry. Not so with the latest storm as we found out. Our trip was not totally wasted. We determined a field trip near Wilkerson Pass (9500ft) should be cancelled due to snow and instead of restaking claims we rockhounded on a sunny unclaimed area near Lake George (elev 8200ft). Elevation makes quite a difference with spring storms. I even managed to find a pocket of smoky crystals. By midafternoon over half the snow was melted and this helped me find a pocket. The pocket was small and the crystals were beaten up for the most part. Still it was my first find of the year.

Doing the forest service work, this tree has been across the rd for 6+ months!

Marker was thrown by someone into this brush pile. Supporting rock caron was about 50ft away down the hill

Pretty small crystal cache from pocket discovery, couple good ones I think

Still snow at Wilkerson Pass. Temperature was 23F on west side of pass near Hartsel. Time to go back to Lake George where the sun is shining and find those crystals depicted above!

Club Field Trips

Our club, the Colorado Springs Mineralogical Society is a great way to get access to otherwise claimed sites and work with others who are more knowledgeable about the minerals on the claim. I enjoy field trips to places I have never been, especially when they are normally inaccessible. In the fall of 2012 our club with the owners permission went to two claims near Salida CO. The Sedalia and Calumet Mines. I'm usually up for any crystal hunting especially when I'm told the crystals could be big. Below are some pictures of various crystals/minerals I collected. Both claims were former mines that took out copper and iron. The mines began operation in the late 19th century and have been mainly closed as viable mining operations since WWII. Below are some pictures of some of the minerals I found. First are pictures from the Sedalia copper mine and then pictures from the Calumet iron mine. You can google these mines and find more historical information on each site or read a little more about them in Voynick's book "Colorado Rockhounding".

Nice goose egg size Almandine Garnet. I found a couple almost the size of 12" softballs.

I think the one just above this caption was about softball size

Fairly large grouping of magnetite

Copper minerals, maybe some Chrysocolla

Actinolite, maybe some magnetite as well.

What follows are some pictures of crystals from the Calumet Mine

Clear quartz on gray background. Epidote inclusions near quartz base

Epidote in Matrix

Nice epidote perched on matrix

Rockhounding 2013 A New Season Ahead

Well, I hope we have better weather this year than we have had so far. Having completed tax season where I work, I've been patiently waiting for a decent break in the weather to get back to prospecting. I finally ventured forth yesterday with my rock hounding buddy, but the weather chased us off the mountains. We knew it would be touch and go because of the weather forecast and I had hoped we could squeeze in 4 or 5 hours. It was 45F when we started, but periods of light snow and wind finally were enough to make us call it quits. While my digging buddy Bob prospected a nearby hill at Lake George, I decided to redig an area I left off late last fall. There was a seam of quartz and a little yellow mud to follow. Finally the quartz became more prevalent, a seam of clay turned from yellow to reddish brown. Changing colors of clay is always a good sign. Actually any time you find clay with quartz you must dig slowly and with care. After getting through some quartz shards a small pocket opened up with a few collectible crystals. I told Bob afterwards that I can't recall a smaller pocket with 3 inch crystals. I took home only about 5 crystals (1-3inch) crystals and left the rest. It was good to get out, a one mile hike with back pack at 8500 ft was a good first effort for the season. While neither of us found much and the snow and wind made us quit early, it was still good to get out for a few hours.

Mother Nature covered last years dig with water crystals of her own

This is the same crystal below cleaned up some, nice and gemmy with a little character to it. It's always nice to have a little pegmatite with the crystal

Looks promising

Three 2-3 inches crystals ready for cleaning

I look a little ornery this day.... too cold not enough crystals, had to take off 2.5ft of overburden before I got to the crystal containing pegmatite