Huron River Uranium prospect, Huron River, Baraga County, Michigan, USA

Greenockite crystals to 0.2 mm long, partly dissolved from enclosing calcite. Composite image made using Helicon Focus software. See Rocks & Minerals vol. 82 (2007) pp. 298-308. A. E. Seaman Mineral Museum collection.

© John A. Jaszczak

Multiply twinned greenockite crystals to 0.1 mm long, partly dissolved from enclosing calcite. Composite image made using Helicon Focus software. See Rocks & Minerals 82 (2007) 298-308. A. E. Seaman Mineral Museum collection.

© John A. Jaszczak

A field of well-terminated, twinned and transparent golden greenockite coating quartzite. Darker crystals are covered by a copper sulfide. Crystals were revealed from calcite using a warmed solution of sulfamic acid. Collected by Travis Olds June 22, 2010. Canon T3i w/ mirror lock engaged EFS-60 and 49mm tube FOV: 0.7 cm Diffused dual fiber ...

Field of view is 0.68 mm horizontal. Collected 2008 by D. Maietta. Lens: Nikon M Plan 20 F-stop: N/A Mounting: Normal, extension = 105 mm FOV: 0.68 mm Lighting: Dual fiber partially diffused Processing: CombineZP pyramid-do-stack retouched with manual composition

© 2009 DMM

A tangly web of crimson red cinnabar crystals. Canon T3i, 35 mm tube- Raynox DCR 250- Thorlabs aperture- Mitutoyo M Plan Apo 10x, Hejnar Photo micrometer stage. Diffused LED lighting. Helicon Focus-depth map; 72 images.

© Travis Olds

Collected 2008 by author. Field of view is 0.73 mm. Lens: Nikon M Plan 20 F-stop: N/A Mounting: Normal, extension = 105 mm FOV: 0.73 mm Lighting: Dual fiber unfocused Processing: Manual composition with CombineZP pyramid-max-contrast background

© 2011 Dave Maietta

Two black, broken crystals of metacinnabar with cinnabar in a 1-cm vug of crystallized quartz. Collected by Travis Olds summer 2010.

© Travis Olds

A small grain of rock with even smaller veins of yellow tyuyamunite running through it. FOV=0.7cm. Collected by Travis Olds in July, 2010.

A cluster of brown tabular anatase on quartz from the Huron River Uranium Prospect. Travis Olds 2009. Raman spectroscopy confirmed. Canon T3i 149 mm tube- Raynox DCR 250- Thorlabs aperture- Mitutoyo M Plan Apo 10x Hejnar Photo micrometer stage FOV: cropped to 0.83 mm Diffused LED lighting Helicon Focus-depth map

© Travis Olds

Transparent hematite blades, about 2µm thick. FOV is 0.84 mm. Collected 2008 by D. Maietta. Lens: Nikon M Plan 20 F-stop: N/A Mounting: Normal, extension = 210 mm FOV: 0.84 mm Lighting: Dual fiber partially diffused Processing: CombineZP weighted-average retouched with manual composition

© 2010 DMM

A very small, ~0.1 mm cubo-octahedron of uraninite on a black vein of uraninite in quartzite revealed from calcite. It's associated with some heavily etched, bright yellow greenockite. Image composed of 4 images stacked with CombineZP.

© Travis Olds

A 2 mm skeletal galena revealed from calcite associated with greenockite. The top of the skeleton makes a downward facing "E" in this perspective. From the Huron River uranium prospect, collected by Travis Olds April 12th, 2011.

© Travis Olds

Insanely colorful and diverse 1-cm vug of vermiform red cinnabar and golden yellow pyrite crystals along with light green sericite and clusters of brightly orange colored quartz crystals. Collected by Travis Olds summer 2010. Photo by John Jaszczak.

© Travis Olds

Cream-white otavite and calcite coating iron-stained quartz from the Huron River U-prospect. The assemblage is overgrown by bright yellow tyuyamunite and malachite. See daughter photo for an EDS spectrum. Canon T3i w/ mirror lock engaged EFS-60 and 49 mm tube FOV: 9 mm Diffused LED lighting Helicon Focus depth map

Secondary electron image of a ~120 micron bleb of mercurian silver recovered from a diiodomethane concentrate. Taken at 450x from the Huron River uranium prospect.

© Travis Olds

Back-scattered electron image of a ~200 micron grain recovered from a diiodomethane concentrate. Initial EDS data obtained near the center of the grain suggested a high Sb content. A polished thin section prepared from this grain was found to contain a core of mercurian silver with 17.75-19.89 wt% Hg via WDS. The outer shell seen in the image as ...

© Travis Olds

Eye-wateringly-red cinnabar on quartz. Field of view is 2.4 mm horizontal. Collected 2008 by D. Maietta. Lens: Edmund Optics Plan Apo 5X/0.14 F-stop: N/A Mounting: Normal, with tube lens FOV: 2.4 mm Lighting: Dual fiber partially diffused Processing: CombineZP do-stack retouched with manual composition

© 2009 DMM

Apatite (EDS analysis), likely Fluoroapatite per analysis of similar material from this site. Field of view is 1.5 mm. Collected 2007 by D. Maietta. Lens: Mitutoyo M Plan Apo 10 0.28 F-stop: N/A Mounting: Normal, with tube lens FOV: 1.5 mm Lighting: Dual fiber, partially diffused Processing: CombineZP pyramid-do-stack retouched with ...

© 2010 DMM

A 1.75 mm grouping of spiky polycrystalline mercurian silver crystals revealed from calcite. Probably contain between 16.48% and 30.55% mercury. In the top left portion of the image are extremely fine grained red cinnabar crystals. Travis Olds specimen, John Jaszczak photograph.

© John Jaszczak

Chalcocite disphenoids on quartz. Collected 2008 by author. Field of view is 4.6 mm horizontal. Lens: Edmund Optics Plan Apo 5X/0.14 F-stop: N/A Mounting: Normal, with tube lens FOV: 4.6 mm Lighting: Dual fiber partially diffused Processing: CombineZP do-stack retouched with manual composition

© 2011 Dave Maietta

A close up view of a colorful concentration of heavy minerals run through methylene iodide. Contains many things from bluish gray bornite, cherry red cinnabar, golden metallic chalcopyrite and yellow to red-orange colored greenockite. Average grain size is about 0.5mm. Travis Olds 2010.

An image taken under LW UV of "manganoan" calcite (seen as red-orange fluorescence) with "cadmian" calcite (seen as cream-white fluorescence). Microprobe data by Carlson, et. al, as stated in Volume 82, No.4 of Rocks and Minerals has shown that calcite displaying cream-white fluorescence is known to contain up to 14 mole percent of cadmium. ...

© Travis Olds

Tiny (

A ~0.5-cm fountain of deep red cinnabar crystals shooting from a central mass in a vug of crystallized quartz. Collected from the brecciated quartz and slate exposed at the waterfall that bisects the prospect. Travis Olds, summer 2010. Canon T3i w/ mirror lock engaged EFS-60 and 98 mm tube FOV: 9 mm Diffused LED lighting Helicon Focus ...

Several groupings of twinned greenockite crystals to 0.1mm revealed from calcite using sulfamic acid. Collected by Travis Olds, summer 2010. John Jaszczak photograph.

© John Jaszczak

A single bleb of mercurian silver to 0.4 mm with a slight yellowish tinge sitting on brecciated quartz. Black acanthite is also in assocation. The silver blebs rarely exceed 0.25 mm in diameter, and are most often only recoverable from diiodomethane concentrates. Hand samples are rare, and associations with finely crystalline greenockite even more ...

© Travis Olds

Massive bright yellow metatyuyamunite coats this small quartz breccia fragment. Though not analayzed, the massive black coatings at the center and top right are likely coronadite, being a common associate to metatyuyamunite here. The black blebs are similar in appearance to EDS confirmed coronadite samples. Travis Olds, summer 2011. Canon T3i ...

A reflected light image of the p.t.s. prepared from the original grain recovered from concentrate. The two islands are actually connected as a part of the original grain under the epoxy. The outer rind of this grain (found by WDS to have a composition nearly identical to eugenite) exhibits optical properties consistent with those reported for ...

© Travis Olds

Irregular cinnabar crystals scattered over quartz. Field of view is 4.6mm. Collected 2008 by D. Maietta. Lens: Edmund Optics Plan Apo 5X/0.14 F-stop: N/A Mounting: Normal, with tube lens FOV: 4.6 mm Lighting: Dual fiber partially diffused Processing: CombineZP pyramid-do-stack retouched with pyramid-max-contrast

© 2009 DMM

Two very interesting 0.1mm cubes of greenockite after galena from the HRUP. The greenockite crystals a short distance to the left are coated with a bluish copper sulfide. Collected by Travis Olds, summer of 2010.

© Travis Olds

A beautiful spiraling crystal of cinnabar from the Huron River Uranium Prospect, Baraga County, MI. It was revealed by etching away the calcite covering it. Travis Olds specimen, John A. Jaszczak photograph. Spire is roughly 1mm long.

© John A. Jaszczak

Spherical aggregates of black and dirty yellow cadmian sphalerite transition into greenockite. Canon T3i 35 mm tube- Raynox DCR 250- Thorlabs aperture- Mitutoyo M Plan Apo 10x Hejnar Photo micrometer stage FOV: uncropped 3.3 mm Diffused LED lighting Helicon Focus-depth map; 75 images

© Travis Olds

Dark green crystals of volborthite (

Tiny lustrous polycrystalline blebs of mercurian silver that were revealed from calcite. Though unanalyzed, the lack of yellow tinge suggests most of these crystals likely contain only a few wt% Hg. Adjacent to the largest of these lie several black masses of finely crystalline acanthite sitting atop dark golden greenockite. Cauliflower groupings ...

© Travis Olds

Yellow-orange crystals of greenockite to 1.5mm revealed from calcite. Collected by Travis Olds, summer 2010. John A. Jaszczak photograph.

© John Jaszczak

Primary uranium ore from this relatively unknown prospect

This tangly mess of canary yellow greenockite crystals was revealed from calcite using sulfamic acid. Canon T3i EFS-60 and 98 mm tube Hejnar Photo micrometer stage FOV: 0.7 cm Diffused LED lighting Helicon Focus depth map-30 images

Two skeletal galena cubes perched on the tip and base of an elongated orange crystal of greenockite. Interestingly, the cube on the tip has a very small greenockite crystal protruding in the opposite direction. Pale yellow powdery tyuyamunite coats part of the vug and galena. Composed of 6 images stacked using CombineZP. Field of view is nearly 3 ...

© Travis Olds

An unusual antenna-like termination on a crystal of greenockite revealed from calcite. Crystals from the prospect are typically terminated by a pedion, pyramid, or combination of the two, but this one couldn't decide. Travis Olds 2012. Canon T3i 149 mm tube- Raynox DCR 250- Thorlabs aperture- Mitutoyo M Plan Apo 10x Hejnar Photo micrometer ...

© Travis Olds

Bulbous groupings of hematite rosettes surround several oddly shaped cinnabar crystals to ~15 microns in the center of this secondary electron image (20 keV). Specimen was sampled from a larger plate of rosettes revealed from calcite-rich brecciated quartz and graphitic slate next to the waterfall. Charging of this uncoated sample led to line ...

Skinny canary yellow crystals of greenockite stretch to 2 mm in this vug revealed from calcite. Canon T3i EFS-60 and 98 mm tube Hejnar Photo micrometer stage FOV: 0.8 cm Diffused LED lighting Helicon Focus depth map-24 images

Gemmy orange to blood orange crystals of greenockite revealed from calcite using sulfamic acid. Canon T3i EFS-60 and 98 mm tube Hejnar Photo micrometer stage FOV: 0.6 cm Diffused LED lighting Helicon Focus depth map-27 images

Oxidized and fresh chalcopyrite in this small chip collected summer 2021. Also present is green volborthite and uraninite.

This tiny specimen of cinnabar in quartz from the Huron River Uranium Deposit in Baraga County was discovered during my latest trip to Upper Michigan. The vug that contains these cinnabar crystals is approx. 1.5 mm across.

© Paul T. Brandes

Canary-yellow platy microcrystalline tyuyamunite with dark brown euhedral mottramite crystals. Some of the mottramite is Zn-rich and may approach descloizite. EPMA pending. Collected in 2012.

A single acicular crystal of greenockite between volborthite (left) and malachite (right). Collected 12 June 2021.

Slates of the Michigamme Lower Slates Formation are well-exposed along the riverbank. A small cave visible in the distance was apparently excavated by prospectors past. Photographed 8/22/07 by D. Maietta.

© 2007 Dave Maietta

This waterfall is the locus of the Huron River Uranium Prospect. Photographed 8/22/07 by D. Maietta.

© 2007 Dave Maietta

A head on view of the quaint waterfall that bisects the Huron River Uranium and Vanadium prospect. If one sits and waits it's not uncommon to see rainbow trout jumping the waterfall. Taken August 1st, 2010 by Travis Olds.