GEOLOGY OF THE OSSIPEE AREA
The Ossipee Mountains are an outstanding example of a ring dike structure, with only the basement complex of the volcano now showing. The Ossipee ring dike is composed of Albany Quartz Syenite. This material was injected from below during the collapse of the volcano, forming the ring structure. The magma chamber of the volcano (the area inside the dike) is composed of Conway Granite. This is where all of the pockets are found. The crystal-filled pockets formed are miarolitic cavities that were formed during the cooling of the granite. As the granite cooled, joint sets were created, and an injection of material into the joint sets produced the mineralization. A joint is a fracture in rock where there has been no lateral movement along the plane of the fracture (up, down, or sideways) of one side relative to the other. Joints normally have a regular spacing related to either the mechanical properties of the rock or the thickness of the pegmatite layer involved. Joints generally occur as sets, with each set consisting of joints subparallel to each other.
HISTORY OF CRYSTAL COLLECTING IN THE OSSIPEE MOUNTAINS
Visitors to the Ossipee Mountains have found excellent smoky quartz crystals for hundreds of years. They are easily distinguished from similar crystals found in nearby White Mountain localities such as Moat Mountain by their dark root-beer color. The best known collecting areas are Bald Mountain, the Connor Pond locality, Gilman Notch, Grant's Peak, Ossipee Gulch ("Folsom's Gulch"), and Knox Mountain. Most of these areas are now considered played out. Other noteworthy mineral discoveries in the Ossipee Mountains are the pocket beryl found on Bald Mountain, topaz from several localities, large smoky quartz and smoky amethyst crystals from Gilman Notch, and wonderful fluorescent coatings of "hyalite" opal on matrix. Other species of minerals found are monazite, ilmenite, amethyst, fluorite, and phenakite (see table for a complete list of Ossipee minerals).
Granite fissures or miarolitic cavities are locally common and most often contain microcline feldspar and smoky quartz crystals. Most miarolitic cavities in the Ossipee Mountains are very small pockets, typically under five centimeters. To our knowledge, the pocket described here is the largest pocket ever discovered in the Ossipee Mountains. Prior to this discovery, the largest one we had ever seen was the Samuelson Pocket on Bald Mountain, which was about 4 meters deep.
THE SURPRISE POCKET
On 5 May 2008, I received a call from a collecting partner, Lori Chapdelaine of Ossipee, New Hampshire, telling me about a fairly large pocket that a local collector, Chris Pelletier of Wolfeboro had found near Gilman Notch in Center Ossipee, Carroll County. Upon hearing the news, I asked if my longtime friend Paul Beaudette of Springvale, Maine and myself could accompany them to this new site. Even though I have collected in the Ossipee Mountains for twenty-five years, this location was new to me.
The next day, after permission had been given, the four of us headed to the site located on the southwest end of Gilman Notch. A light rain was falling and it was a chilly 45 degrees, but that couldn't dampen our enthusiasm as we set out for the pocket. We hiked up several hundred feet on an old logging road and then bushwhacked through high brush for ten minutes before arriving at the site. Chris showed us the pocket, which opened up at the base of a 1.5-meter-high ledge. The opening was 0.8 meters by 0.5 meters, and the pocket extended straight into the ledge for 1.3 meters, with a dogleg to the right of 0.8 meters. Sliding on my back through the narrow opening, I expected to see some remaining crystals and possibly some matrix pieces. Instead, I was disappointed to find a barren brown tube, with absolutely no crystallization showing. Chris mentioned that he had been in there once a few weeks before but only found some porcupine quills.
We decided to split up to see what we could find. Chris went down the slope and started working the tops of the ledges below the pocket, looking for any crystals that might have fallen out from other pockets. Under some moss he discovered pocket debris, in which he found a few two- to five-centimeter amethyst scepters and some small smoky quartz crystals. I explored below him on the lower ledges, where I split open a large, promising boulder. Inside were several crystallized vugs containing siderite, microcline feldspar, smoky quartz, and a few quartz scepters. I managed to hammer and trim out several hand-sized specimens, but found nothing special.
Meanwhile, Paul asked Lori if she would go into the pocket, as she was the smallest and could fit in easily. She agreed and went in. Once inside, she scratched around the floor and sides of the entire pocket, to see what could be uncovered. After half an hour of work she exposed a patch of dense, hard-packed brown clay on the left sidewall. Paul encouraged her to keep scratching, and in a little while her efforts were rewarded with several five-centimeter sceptered quartz crystals lightly coated with feldspar. Paul yelled down to me with the news and I climbed back up the ledges to see what was going on.
To enter the pocket, I had to lie on my back with my left arm held tight against my side. Sticking my head in, the roof of the entrance was only an inch above my nose. Wiggling and sliding in further was a challenge, but I continued until both shoulders were jammed against the sides of the pocket. To my right I could see the opening Lori had made, where several shiny black crystal tips flashed in the light of the flashlight. The crystals were embedded in dense brown clay and appeared to be orientated tips down. Using a metal finger, I scratched at the hard pack clay to expose the shoulders and sides of the first crystal. When I had 3 inches of crystal sticking out, I grabbed it and wiggled it back and forth until it reluctantly popped out of the clay. To my delight I held a twelve-centimeter-long crystal, still slippery with mud, but not so coated as to hide the outlines of a scepter head sitting on a short, narrow shaft!
Because I was jammed into the pocket in such an uncomfortable, cramped position and could only work with one hand, my arm tired rapidly, and I had to take frequent breaks. Lori and I took turns in the hole, working more crystals out of the dense clay. Each time one of us emerged from the hole with another crystal, we would gently scrape the clay off and marvel at their size and shape. We spent the entire afternoon pulling out crystals, getting wet, dirty and happy. At the end of the day we divided up our finds, and Chris was given first pick. He chose the best piece: an eight-centimeter-diameter, thirteen-centimeter-tall smoky quartz scepter.
When I reached home, I took the freshly dug crystals into my workshop, where I began washing and brushing until the clay coating was gone. The crystals were well formed, some with scepter heads and very short, narrow shafts. These were smoky quartz crystals with a secondary overgrowth of lighter material that produced the scepters. The secondary growth included in the faces gave them a reddish-tan hue that almost looked enameled. This contrasted with the white/clear quartz on other faces of the crystal. As we went deeper into the pocket, this overcoat changed to a glassy clear secondary growth with bladed hematite inclusions.
Later in the week Paul and I returned to the site alone and continued to dig in the pocket. We removed several more pieces before muscle cramps and a failing flashlight ended our efforts. At this point we had enlarged the original clay opening until it extended 1 meter beyond the confines of the original hole. When we reluctantly packed up, we made plans for a quick return to dig out what appeared to be a large crystal on the right side of the new hole.
The next week, Paul, Lori, and I returned to continue working the pocket. Lori commented, "I think this is going to be a big pocket." I disagreed, figuring it was just an offshoot of the original pocket. To my surprise, after several hours of wet, dirty excavation of more and more hard-pack clay, we had widened and deepened the hole until it was 1 meter wide by 1.3 meters deep. The feldspar-coated smoky quartz crystals, some up to 23 centimeters in length, were still coming out of the clay.
On our next trip to the pocket, Paul and I invested three hours of backbreaking, rock-breaking labor in order to widen the initial opening to make access easier. This meant I could now lie on my right side once I slid into the pocket on my back. The pocket was heading into the hillside and was following a joint set. We decided that digging out the dike would provide better access.
A few days later we returned to the site, where we found Chris and several friends working the pocket. They invited us to take turns in the pocket, so we all could collect something. The pocket was getting longer, but the working conditions were still challenging. When digging, I had to lie on my back with the rock ceiling just one inch above my chest, and then scratch at the clay with a metal digging tool to expose crystals. At this point I was able to slide in on my back so far that I was completely inside the pocket. After fifteen minutes of hard work the air would get bad, and I had to slide back out. The working face in the pocket was now a semicircular band about 2 meters long. The crystals were in a layer about 0.8 meters thick. It appeared that the bigger crystals were running in a line parallel to the joint set. The patina on the crystals had changed, and was now quite transparent, making it easy to see the many hair-like inclusions of hematite. That day I carried out a pack filled with 30 kilograms of crystals.
Later that week, Paul and I went in and dug out the joint set/dike, to improve access. We continued to excavate along the joint set until we encountered a large dome of aplite that was the outer shell of the pocket. Normally if you are working through granite towards a pocket, the granite will get coarser. Hopefully, it will next turn to aplite, a fine-grained, very hard granite. These are the prime signs that you are heading toward a pocket. We figured that the dome was 0.8 meters thick. We made plans to come back with Paul's Cobra drill and punch a new opening in the top of the pocket.
The final time that Paul, Lori, and I went to the locality was on 21 May, 2008. When we arrived, we found two other people working the pocket. Chris had told them about the find, and they had arrived early. They had a pile of crystals stacked up and offered to let us take a turn. The pocket was now over six feet long and three feet wide and three feet high. Lori and I worked together and were able to remove several basketball-sized crystals. After a short while eight more people showed up, and took over the pocket. The situation deteriorated quickly, and Paul, Lori, and I left and did not return.
Over the next week, the group that had taken over the pocket emptied it of every remaining crystal. We heard stories of threats, vandalism, and serious damage to crystals in the pocket, by amateurish and haphazard removal and handling of the crystals. Instead of patiently working the clay away from each crystal, these people pried out the large smoky quartz crystals and complex clusters with metal bars, causing most of the crystals and clusters to split and ruining what would have been prize specimens.
This pocket contained only four mineral species: microcline feldspar (highly weathered), smoky quartz, siderite, and hematite, (as inclusions in the quartz crystals). Almost all of the crystals we found were concentrated in a horizontal band of clay, about .8 meters thick, which rested on the floor of the pocket. Originally, the crystals must have been attached to the ceiling. During pocket decompression, they broke loose and dropped to the floor. The floor consisted of weathered feldspar clay and debris, so not all of the terminations were damaged in the original fall. Some time after the decompression, another influx of solution entered the pocket, and the original crystals started to grow again. This new deposition of smoky quartz produced many double-terminated and sceptered crystals. Hematite dissolved in this solution created the reddish-gold hairs inside the crystals. This was when many of the crystals with broken ends re-healed, forming new points. The siderite was deposited at the end of this sequence. At some later time, the pocket roof cracked, probably under the weight of glacial ice, allowing a slurry of clay and soil to fill the pocket.
In August I returned to the pocket to measure it and take some pictures. After excavation, it was 5.5 meters long and 1.3 meters across. I took pictures of the empty pocket, the trash left at the site, the tools lying around, and the ashes of a large fire. Several of the individuals involved in cleaning out the pocket later approached local mineral dealers to sell some of the crystals. They offered damaged, non-aesthetic specimens, so few were taken. The fact that so much material was dumped on the market at one time also lessened the price. Damaged crystals and cheap prices: that is what happens when inexperienced collectors do not take the time and care necessary to properly recover crystals from any pocket.
I named this discovery the Surprise Pocket because it was a surprise to find it, and because every time I worked it I was surprised again, as the pocket got bigger and bigger, and the crystals got bigger and better. But in light of all the problems that arose, perhaps it should have been called the Stampede Pocket.
All collecting areas in the Ossipee Mountains are on private land. Visitors planning a collecting trip should contact the property owner and obtain permission before paying a visit to any collecting site.
Like everywhere else, the collecting of minerals in the Ossipee Mountains is being threatened by a number of factors. Due to issues such as the increase in new home construction, the exhaustion of known sites, posting of land, and collectors trashing areas without regard for the property owners' rights, this entire area is in jeopardy of being closed to collecting. For example, after being open for decades, most of the Gilman Notch area is no longer accessible because the landowner was appalled and angered by the the extent of devastation from a few years of hard collecting and the trash left at the sites.
We are indebted to Chris Pelletier for discovering the locality and to Lori Chapdelaine and Paul Beaudette for their energetic digging and never-ending patience. Thanks are also extended to Bill Metropolis for critically reading the first draft of the article, and to Bob Cook for reviewing the manuscript and helping to prepare it for publication. We thank Dr. Robert L. Reuss, Professor Emeritus of Geology, Tufts University, Medford, Massachusetts for the SEM work that identified the hematite inclusions, and to James Young, Groton, Massacusetts for expediting the SEM work.
ABOUT THE AUTHORS
Jonathon Herndon has been an ardent field collector for over 25 years, with a special focus on the Ossipee Mountains since 1983. He has a BS in Geology from the University of New Hampshire. He has written several articles for Mineral News, and actively promotes the earth sciences to mineral collectors.
Eric S. Greene is an avid field collector. He operates Treasure Mountain Mining, an on-line business which sells mineral specimens on eBay. He wrote an article on pyromorphite from Loudville, Massachusetts that was published in Rocks & Minerals Vol.76 (2), and has authored several articles for Mineral News.
Minerals Reported From The Ossipee Mountains
Art Smith reported almost all of the minerals on this list in his article in the New Hampshire issue of Rocks & Minerals. The primary specimens targeted by collectors in the Ossipee deposits are large smoky quartz crystals, which lure collectors in search of big pockets full of crystals. Most of the other species on the list are found in association with miarolitic cavities in which the scarcer elements were concentrated as the magma cooled. All of the more exotic minerals are scarce, and are typically found in small or micromount-size specimens. A small amount of gold from Diamond Ledge was reportedly shipped to the Philadelphia National Mint in the 1870s.
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