The 2000 Season at the Orchard Mine
A view of the headwall taken September 16, 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
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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