Sunday, November 13, 2011
Collecting at Sugar Grove, West Virginia
West Virginia? Aside from the meager Sugar Grove road cut locality in Pendleton County, I often wonder what else this state has to offer the mineral collector and why more information is not available. Considering the abundance of localities in all the states that surround West Virginia, such a dearth of mineral localities doesn't seem to add up. And certainly should not some of the geological activity that formed all those mountains left the state with more places to collect?
Pictured above from left to right at Sugar Grove are Robert Miller, Patrick Haynes, Maureen Campeau, and Stephanie Thi, all having a wonderful time breaking open chunks of basalt freed from the the shale into which they intruded millions of years ago. Therein are endless vugs which bear a variety of mineral species that can be quite spectacular when viewed beneath the scope.
Particularly notable is filiform pyrite, one of the most intriguing of this common mineral's numerous morphological forms. Filiform pyrite is has crystallized in the form of needles, which sometimes bend at right angles. Often at Sugar Grove, these needles are associated with the soft iron-rich clay silicate mineral nontronite, which can range in colour here from a light gray-blue to greenish black. At left is an example where the filiform pyrite has threaded dark spheres of nontronite. A right angle bent pyrite crystal coated with light bluish gray nontronite is shown at right. Microscopic pyrite crystals of other habits occur at Sugar Grove as well. Intergrown cubes are particularly prevalent
Chabazite (variety phacolite) is also notable amidst Sugar Grove's bounty. The larger crystals are easily identified. Smaller crystals that are visually quite similar to the phacolite, however are unfamiliar enough to stump me on visual identification. In the image at left, the larger 7mm. crystal to the right is obviously phacolite, but the smaller crystals to the left of it, I'm not so sure about. Included among them could be analcime and harmotome perhaps chabazite of a different habit, possibly even calcite, which is also common in these vugs, occasionally in the largest crystals of any species known to occur here.
Less common, but fun to find, is mesolite. Over three hours of cracking open rocks and peering with my loupe into vugs, the piece shown at right was the only mesolite that I, or to the best of my knowledge, anyone in our group came up with.
Though the collecting was better than expected, the locality was quite different than what I'd expected to find. It is an unremarkable looking road cut on the west side of Sugar Grove Road about 12 miles south of its intersection with Route 33. Needless to say, the area is quite rural. A possible landmark approximately 100 yards to the north on the opposite side of Sugar Grove Road is a couple of sheds, one with open sides, and a possible presence of a few old farming and/or construction vehicles and equipment.