David Fryauff (2)'s Photo Gallery
CGX-5ALCopper Cu , Cuprite (Var: Chalcotrichite) Cu2O , Tenorite CuO
Dimensions: 18.0 mm x 6.0 mm x 3.0 mm
Field of View: 22.0 mm
Weight: 0.45 g
This small piece of dendritic copper hosts sparkling red chalcotrichite and powdery black dendritic growths of tenorite. The attached child photos show close-up views of the chalcotrichite and tenorite.
N2D-J79Dolomite CaMg(CO3)2 , Chalcopyrite CuFeS2 , Siderite FeCO3 , Chalcocite Cu2S
Dimensions: 4.8 cm x 3.2 cm x 2.2 cm
Field of View: 4.0 cm
Weight: 30.5 g
Nodular dolomite with micro-crystals of black chalcopyrite and reddish-brown siderite from the Flambeau Mine in Ladysmith, Wisconsin. The tetrahedral chalcopyrite crystals may be covered with a patina of black chalcocite and bornite. This dolomite specimen bears a striking resemblance to several other Flambeau Mine dolomites that were collected by Bill Cordua during the short but productive life of this open pit mine that produced copper, gold, and silver. After only 5 years of production, the ore body was depleted, the pit was backfilled and the site was fully reclaimed. The attached child photos show close-up views of this specimen.
0FF-J55Manganese Oxides (Var: Manganese Dendrites), Aragonite CaCO3
Dimensions: 2.8 mm x 1.8 mm x 0.3 mm
Field of View: 27.0 mm
Weight: 1.85 g
I did not collect these small rocks from Egypt's White Desert National Park, but in a wadi south of the Farafara Oasis near an unusual raised formation of crystalline calcite that contained layers of coal. In a short time I picked up several small pale beige rocks, and was surprised to see that many of them had complex and intricate markings of black manganese oxide dendrites. The largest of these stones measured 6.3 x 3.4 x 3.8 cm and weighed 68.5 g. The smallest of 10 specimens is shown here. Each one reacts vigorously to 2.5% HCl and the pale matrix of these specimens gives off a strong yellow-white fluorescent response to SW and LW UV light. It is suspected that these may be marine-derived or biogenic aragonite of Cretaceous-Eocene geologic origin. Clear and translucent calcite from the nearby "crystal hill" locality produced a very different weak, pale white fluorescence. Typically, the surfaces of these exposed stones had been polished smooth by centuries of wind-blown sand. The attached child photos show the collection and a close-up of the manganese oxide dendrites in the smallest of these specimens.
3XN-UK6Pyrite FeS2
Field of View: 10.0 mm
Largest Crystal Size: 5.0 mm
Thanks to Sam Linton for collecting this specimen in the vicinity of the No. 9 Coal Mine in Lansford, Carbon County, Pennsylvania.
PG9-VT7Siderite FeCO3 , Vivianite Fe2+Fe2+2(PO4)2·8H2O , Limonite
Dimensions: 8.0 mm x 8.0 mm x 4.0 mm
Field of View: 3.0 mm
This micromount of vivianite and siderite from Henderson, Caroline County, Maryland was collected and made by Bob Cox and labeled No. 485. Portions of his collection were on the giveaway tables at the 2024 Leidy Microscopical Society Micromineral Symposium in Philadelphia. Mindat does not list siderite for this locality but clearly, it is siderite that dominates in this photomicrograph. The vivanite on the upper right part of this specimen seems hardly recognizable and may have been broken during the preparation of this micro. Yellow ochre limonite and bog iron ore may be fairly common in the Atlantic Coastal plain of eastern Maryland and much of Delaware.
5F5-8JRFluorite CaF2 , Quartz SiO2
Dimensions: 6.0 mm x 5.0 mm x 3.7 mm
Field of View: 7.0 mm
This view shows tiny groups of quartz crystals on pitted octahedral fluorite. Thanks to John Kress, I am the first to post a mineral photo for this interestingly named mine/prospect. The Cuchillo Negro District was known for lead, zinc, silver, copper, gold, and iron deposits. However, fluorospar/fluorite may have been the only real production of most of these mines. No other information is available for the Bootlegger Mine except a possible reference in Rocks & Minerals (2009) 84:15.
CHD-C1ECalcite CaCO3 , Quartz SiO2 , Chlorite Group, Celestine SrSO4
Dimensions: 25.0 mm x 15.0 mm x 10.0 mm
Field of View: 1.5 mm
This 1.5 mm FOV shows a micromineral found in 2 small samples of quartz + calcite + 'chlorite gp' from the Blue Ball Stone Co. limestone quarry in Lancaster County, Pennsylvania. It was obtained from the giveaway tables at the 2024 Micromineral Symposium of the Leidy Microscopical Society held in Philadelphia, Pennsylvania. Within the limited Mindat listing of 12 valid mineral species for this locality, the thin, radiating, lath-like crystals with sharply squared tips suggest either gypsum (monoclinic) or celestine (orthorhombic). The Mindat description of the crystallography of celestine specifically reports a lath-like morphology as well as fibrous veinlets with parallel or radiated fiber structure. This description leads us to suspect celestine as the mineral in question. These well-formed crystals are surrounded by fields of a mineral with less-ordered and a more fibrous morphology. Interestingly, despite iron oxide staining both the lathes and fibrous tufts give off a weak pale-cream response to LW UV light. The Blue Ball Quarry is currently filled with water and the rim is planted with crown vetch. It may be worthwhile to examine more closely other specimens that have been collected from the Blue Ball quarry to better understand and define its mineralogy. Additional photomicrographs of the lath-like and fibrous forms are attached.
4RQ-M9LCalcite CaCO3 , Muscovite KAl2(AlSi3O10)(OH)2
Dimensions: 19.0 mm x 16.0 mm x 13.0 mm
Field of View: 22.0 mm
Weight: 4.2 g
This small specimen of calcite from the collection of Barry Remer has a hand-written label giving the locality as "185 St., N.Y. N.Y." That places it in the Washington Heights neighborhood of Manhattan Island. This location is 7 blocks north of the Trans-Manhattan Expressway (I-95 & US1) that crosses the Hudson River to Fort Lee, New Jersey via the George Washington Bridge on the west, and which crosses the Harlem River, on the east, to the Bronx. This purported NYC specimen is rather poorly crystallized but under either LW or SW UV this calcite lights up with a surprisingly bright red-orange Franklin-type fluorescent response. The attached child photo shows the fluorescent response of this Manhattan Island calcite to LW 365 nm UV.
G5T-M6WPyrite FeS2 , Quartz SiO2
Dimensions: 24.8 mm x 21.4 mm x 14.2 mm
Field of View: 15.0 mm
Largest Crystal Size: 9.4 mm
Weight: 11.94 g
This pyrite crystal, nicely perched in a matrix of phyllite and quartz has a notch out of its corner that looked like an injury sustained in breaking off the excess matrix. However close microscopic examination could detect no sign of damage and revealed this "defect" to be the unusual but completely natural form of this crystal. Sincere thanks to whoever donated this classic Blue Ball limestone quarry pyrite specimen to the giveaway tables at the 2024 Leidy Microscopical Society Micromineral Symposium in Philadelphia, PA. The attached child photo shows a closer look at this "missing" corner.
N3K-EFDBabingtonite Ca2(Fe,Mn)FeSi5O14(OH) , Calcite CaCO3
Dimensions: 4.7 cm x 4.0 cm x 2.4 cm
Field of View: 4.0 mm
Largest Crystal Size: 2.0 mm
Weight: 41.1 g
This miniature-size specimen must have been collected long ago but never made it into a collection because of the small size of the babingtonite crystals. I acquired it off the giveaway tables at the 2023 Desautels Symposium in Baltimore. Translucent calcite crystals cover half of the surface of this prehnite and give off a nice pale pink fluorescence under LW UV light. Hematite is also present as 1-2 mm platelets. The attached child photos show other babingtonite micro-crystals on this piece.
