Without doubt, the most difficult mineral to be recovered at the C.E. Duff and Son Inc. quarry is Sphalerite. Sphalerite is generally found as small, sharp, dark red, hextetrahedral crystals lining pockets and crevices with Dolomite.
The best Sphalerite crystals were commonly observed at the base of the upper level viagra est il. Recently, Sphalerite has been more common in the second level of the quarry. Unfortunately, pockets larger than 1 cm are rare in this part of the operation.
Sphalerite will form sharp, dark, ruby jack, single crystals up to 3 millimeters, or infrequent twinned multiple growth crystal clusters up to 1 cm. Multiple growth crystal clusters of that size are extremely rare. T
he photo to the left displays typical multiple growth crystals from this locality. In contrast, the photo to the right displays the more common Sphalerite crystal habit from the Duff Quarry.
Due to the uncommon nature of this species at the Duff Quarry, quality specimens of Sphalerite from this locality are typically well appreciated among knowledgeable collectors.
At this point, this collector would like to thank the owners of the C.E. Duff and Son Inc. Quarry for their past generosity of allowing specimens to be preserved for study. Many at this operation are aware of the tremendous significance of these specimens to mineralogists, mineral enthusiasts and educators both locally and world-wide.
The study of the mineral habits at this locality are especially important to a more complete understanding of Ohio mineralogy. Without their generosity, this type of study would never have been possible. Their understanding and regard for such research is greatly appreciated.
The many years of limited and controlled safe collecting made available through their kindness has afforded collectors with high quality specimens from this classic Ohio locality. It is the hope of this collector that this information will help mineral enthusiasts understand and more greatly appreciate the history and development of minerals from this locality.
Unfortunately, this article cannot attempt to cover every mineral habit which occurs or has occurred at the C.E. Duff and Son Inc. quarry. Mineralogically speaking, this fruitful quarry has surely produced other distinct mineral forms in its nearly 50 years of operation.
Certainly, further study is warranted on the many complex pyrite forms and other mineral habits found at this quarry. For other related information on the minerals of this locality, see the reference list below.