Mining at the Orchard and GE Quarries
Oxford County, Maine

Coromoto Minerals
The 2001 Season  at the Orchard Mine

The Orchard Pit headwall July 15, 2001

The Pegmatite Widens and the Chemistry May be Changing

3 years of mining at the Orchard finally brought us to the  road at the eastern end of the pit. This is 120' from where we started. The pegmatite from the 80' to the115' mark had narrowed considerably and was further restricted by schist zenoliths within the vein. This pinched zone produced abundant pockets with quartz crystals. Some of them were over 2' in length. So, if one was a quartz enthusiast, this zone was heaven. Staring into this pinch, the faint of heart could convince themselves that we would see the fat lady when the dust cleared from the next blast. What argued against this conclusion was that the pegmatite beyond the road could be traced for at least 100' eastward. The last 10-15' of pegmatite in front of the road fortunately had taken a decisive turn for the better.  The pegmatite, which showed precious little quartz in the pinch save crystals, was now turning much coarser with microclines and quartz pods. Beryl, which had not been seen for the last 40', was now becoming commonplace. The schist cap, that had covered the pegmatite since the begining continued. Interestingly  the pegmatite appears as if it had extruded around the cap in the region where the peg improved.

In order to continue mining, preparations had been started last year to move the road 100' eastward and beyond the original Orchard prospect. This small pit had been opended sometime prior to 1940. Once digging out of the road commenced, the volume of dirt necessary to move had been considerably underestimated.. As the dirt was being removed by Richard and Mike, theey were surprised to encounter a very large quartz mass beneath. The mass was larger than any quartz pod so far encountered at the Orchard. Setting on the  footwall side, it stretched for more than 40' along strike. Associated with this quartz were very large microclines, apatites and green and blue beryl. Large masses of rose quartz were also later found in the couple of rows put in at the western end of the mass. In the photo, some large microclines are visible. The pegmatite, as mentioned, can be seen to flow around the schist cap.  Above this cap, both the footwall and hanging wall contact are visible. Richard has just finished hosing the area down.

The feldspar within the pegmatite  below the schist cap was decidedly more white than previously encountered at the Orchard. Besides appearing more soda rich, some of the beryl in this white spar was strikingly blue. Although  matrix beryl, it was indeed the most blue we have found so far. Mary recovered these nice aquamarine crystals from some of this white feldspar.

During the 2nd week of July we benched the headwall back about 6' and drove this bench down almost to the floor. Once down on the bottom ,each successive bench  became more mineralized as we moved toward the current headwall. Blue apatites and bertrandites were beginning to appear. These, coupled with 

plentiful maganapatites in the feldspar and columbites in both the quartz and the feldspar, encouraged us. The pegmatite had widened back to its prior width as well. As we wrapped up this round of mining,  the density of beryl within the quartz and feldspar was increasing rapidly. There was very little of the pegmatite that did not show beryl of some color. Some of these were intensely blue. The matrix specimen above has a steely blue core.  Richard and I began to wonder whether the chemistry of this portion of the Orchard was more diverse than what we had seen before. The intense blue of the beryl made me wonder whether scandium was not beginning to appear. There is some speculation in the literature that scandium may play a role in very blue beryl. In the main photo at the top of the page, a dark band can be seen on either side of the more coarse zone. Especially on the right and at the bottom of this dark band many of the beryls were quite etched and some had been completely or partially altered to bertrandite. Some larger beryl casts were completely filled with a paste of bertrandite. Several nearby vugs were filled with gemmy  albite and blue apatites. 

On the last day of this session the morning shot  revealed the most bertandite and blue apatites so far. Beryl was evident everywhere. Richard and I decided to take one more small bite out of the base of our headwall. We drilled two 6' holes into a protruding section near the center of the vein. We hoped to break the pegmatite just outside of the etched band on the right of the pegmatite. Although our shot did not break where expected, our effort revealed a very large green beryl (8 cm across the face) and a smoky quartz pod between microcline blocks. Smaller blue beryls sat above the larger one. In the photo above, strong mineralization can be seen to the right and below the quartz pod.

In the last 2 days we had set up our electric water pump and used a garden hose to wash down the newly exposed material. This procedure is vital as it readily reveals mineralization of interest that might otherwise be missed in the blast dust or washed away by our larger gasoline driven water pump. ( We should have done this much earlier.) Pulling back the muck at the base, a little washing produced the first beryl pocket of size since last August. The pocket, about fist size with radiating chambers, had 5-6 beryls projecting across its interior. These beryls were not especially gemmy but they were etched in a different manner from other pocket beryls at the Orchard. Rather than the faceting type etching seen before, the etching ran in long grooves parallel to the 'C' axis. The crystal terminations were quite pitted. After washing , one of the larger crystal segments (3 cm) revealed 6-8 small curious crystals on a green overcoat material. Although we exchanged in some creative idenfication for a while, SEM revealed these crystals to be only albites. We'll just have to keep digging.


Go To August 2001 -Fluorapatite pocket

Return to Home Page