Mining at the Orchard and GE Quarries
Oxford County, Maine

Coromoto Minerals
The 2000 Season  at the Orchard Mine

A view of the headwall taken September 16, 2000
September, 2000


I returned to the Orchard Pit determined to discover what lay ahead of and under the quartz pockets opened in August. Getting down to business, several shots in the pegmatite around them revealed yet more of these barren pockets. Only on the hanging wall side and near the contact were we to find pockets with anything other than quartz. These were filled with bertrandites and the occasional beryl nodule that had escaped complete dissolution. Around these barren pockets was no massive quartz or blocky spar as we moved ahead. Only fine grained spar was encountered. Always on the lookout for phenakite and other beryllium minerals, none were observed.
 

With this effort we were now at the limit of our reach at the bottom. Our next task, and a most unpleasant one, was to go back up to the top of the headwall and move it back. We took another 12' and descended along this bench 40' to the bottom.  This work exposed not a single beryl or quartz pod. After cleaning the pit out completely, we placed a shot into the floor at the base of the headwall. This small blast exposed small smoky quartz masses with crude yellow and green beryl and abundant large columbite-tantalite crystals frozen in feldspar. This rare earth  zone was immediately in back of  the large quartz pockets found in August.

Since we had the pit cleaned to the bottom, it was our chance to re-visit the zone just west of the large quartz pockets and 10' above them. As can be seen in this photo, the zone appears to be  core with beryls above the massive quartz and blocky feldspar. Within these quartz masses were large areas of rose quartz-again another indication of core.  Note the pocket exposed just below the shovel. This pocket was filled with quartz crystals on the right and a micaceous mud on the left. Several other pockets were encountered drilling but were not opened.  In the next photo the portion of the zone at the upper right is shown. This area lay just underneath the large etched out feldspar pocket encountered late in '99.
 
 

 

The richness of the beryls is evident here. Just above the shovel in the prior photo a quite blue beryl rests in quartz matrix. Immediately below this beryl the quartz was rosy. Sections of this shattered beryl are cuttable. One other quite intense blue beryl was found within the rosy section of this pod as well.

Already in August the back wall was devoid of quartz masses and seemed to consist entirely of border zone mineralization. The pegmatite had narrowed somewhat and in addition was choked in the middle with  a schist xenolith lying vertically for almost 40'. As can be seen in the large photo above, the floaters were surrounded by a fine grain spar that had taken on a bluish tinge from the schist. The oxidized zone at the left lead all the way to the surface of the pegmatite and left in its wake vuggy brecciated feldspar that nearly claimed two 8' drill steels.  The next bench back however revealed pockets developing around these included masses. In these pockets were fine gemmy quartz crystals and grey and green apatites.  What was remarkable here was the abundance of the apatites. Also revelaed in this bench was that theschist inclusionswere become less massive and breaking up into isolated blocks. If one has any doubt as the the contribution of these inclusions to the production of pockets, one need look only at this new face. Each of the schist blocks sat within a rind of pocket from walnut size to basketball size. A new feature appeared as well. Almandine garnets appeared in bands surrounding some of the blocks producing an interesting color play from grey to red to green to white. Doug described the back face as looking like a candy store.

It is becoming more clear as we mine the Orchard that each producing beryl pocket zone sits above a system of etched out pockets. It is probable that the many beryl casts observed within these pockets contributed their beryllium to the formation of the beryl within the pockets above. The small amount of bertrandite and phenakite found can not possibly be the repository of the original beryl.


Blue beryl in rose quartz
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