Big Chief Mine, Glendale, Keystone Mining District, Pennington County, South Dakota, USA

Silky white acicular crystals to 0.75mm in phosphate nodule including Ludlamite, Siderite and Quartz.

© Tom Loomis

Black perloffite crystals in a vug of ludlamite from the Big Chief Mine.

© Zach Berghorst

Lustrous dark red-brown crystal. A very large crystal of this very rare species. EX: John Dagenais collection, originally obtained by him from Willard L. Roberts. One of the best examples of this species. Robert O. Meyer specimen and photograph.

© 2004 Robert O. Meyer

Spray of whitmoreite crystals. Doug Merson photo and collection.

© 8/2016 Douglas Merson

Brown pseudo-octahedral 1.4 mm tall crystal on Siderite. Robert O. Meyer specimen and photograph.

© 2004 Robert O. Meyer

Monoclinic crystals of perloffite. Brent Thorne specimen and photograph.

© Brent Thorne

A 5mm group of crystals on matrix. Photographed by, and in the collection of, Karl Volkman.

© Karl Volkman 04/05

Field of view 4 mm. Collection M. Kampf No 87-063.

Width of field is 1.8 mm. Collection of Jesse Crawford. The depth of field has been enhanced using Helicon Focus (5 exposures). Equipment: Nikon D-100 on a homemade microscope.

© 2008 by Jesse Crawford

Pale ludlamite crystals in a small vug. FOV is 10mm across. Rick Dalrymple Specimen & Photo.

© Rockpick Legend Co. & Rick Dalrymple

Greenockite - close-up rich yellow coating.

© Christopher O'Neill

Shiny reddish-black crystals of kryzhanovskite on matrix. FOV is 10mm across. Rick Dalrymple Specimen & Photo.

© Rockpick Legend Co. & Rick Dalrymple

Phosphophyllite crystals from Big Chief Mine, South Dakota. Retains label from Mineralogical Research Company.

Brown flattened whitmoreite crystals & light-green sharp tabular ludlamite. Olympus OM DE M5 Mark II.Mitutoyo Plan Apo X 5 /Achromatic doublet retro/ Aperture. Photo & Collection Christophe Boutry.

© Christophe Boutry

Black kryzhanovskite crystals on matrix. Small elongate black crystals are likely rockbridgeite.

© Zach Berghorst

Tabular dark-brown perloffite crystals cluster on green ludlamite. Olympus OM DE M5 Mark II /Mitutoyo Plan Apo X 20/Raynox Dcr 250 Retro/Stack Unit Linear-actor & Control/ Aperture. Photo & Collection: Christophe Boutry.

© Christophe Boutry

Phosphophyllite crystals from Big Chief Mine, South Dakota. Retains label from Mineralogical Research Company. Some of these crystals are double-terminated

White acicular loomiste crystals. Photo courtesy of the RRUFF website.

© RRUFF website

Very small crystal fragment of olmsteadite with interesting internal fractures. Analyzed via Tin Can Hill Minerals. Fragment is about 0.4 mm across and is mounted in a plastic capsule.

Bright yellow, compact fibrous, crystal group. XRD RRUFF lab. The color is actually brighter yellow than photo. XRD, Raman RRUFF lab.

Phosphophyllite crystals from Big Chief Mine, South Dakota. Retains label from Mineralogical Research Company. Some of these crystals are double-terminated

Blocky crystals of pale green ludlamite, with brown phosphosiderite, in a specimen of altered triphyllite also containing crystallized vivianite, siderite, pyrite, quartz, ferrisicklerite and gypsum. I am not sure what the pale tan crystals are. ex. Julius Weber S420-299 N4026N

© 2021, JGW

Orange brown spherulites of Earlshannonite on and with faint pink Hureaulite. Also associated are prismatic bottle-green Arrojadite. XRD by RRUFF lab.

This is a micromount specimen of whitmoreite from the Big Chief Mine (Johnson pegmatite), Glendale, Keystone Mining District, Pennington County, South Dakota. I acquired the specimen from Don and Mary Jane Smoley at the 2023 Mansfield mineral show. This specimen was in the former collection of Robert Rothenberg (1943-2021): #18474. Bob acquired ...

© Jamison K. Brizendine

Phosphophyllite crystals with numerous tufts of yellow-brown Whitmoreite.

© Zach Berghorst

Blue platy crystalline vivianite, pale green ludlamite and brown phosphoferrite in a specimen of altered triphylite, also containing siderite, pyrite, quartz, ferrisicklerite and gypsum. ex. Julius Weber S420-298 N4026N

© 2021, JGW

This is a micromount specimen of phosphophyllite with whitmoreite from the Big Chief Mine (Johnson pegmatite), Glendale, Keystone Mining District, Pennington County, South Dakota. I acquired the specimen from Don Smoley at the 2023 Erie mineral show. This specimen was in the former collection of Robert Rothenberg (1943-2021): #01103 - 05. ...

© Jamison K. Brizendine

Murky green, unusual prismatic habit of Ludlamite. ID by Raman.

© Tom A Loomis

Strunzite crystals from Big Chief. From the Dan Behnke Collection #14573.

Dark green tabular rockbridgeite cluster. Sony Alpha 7R ii/Mitutoyo Plan Apo X 20/180 mm Achromatic doublet retro/"Stone Master Stack Unit "/ Linear-actor & Control/ Aperture. Photo & Collection: Christophe Boutry.

© Christophe Boutry

Salmon-colored Hureaulite with greenish Ludlamite from the Big Chief mine. Phosphoferrite associated but not photographed.

Partial crystal of olmsteadite. Acquired from Dakota Matrix Minerals. Brent Thorne specimen and photograph.

© Brent Thorne 2020

Tiny red-brown, tabular fragment of olmsteadite without matrix, photographed through a capsule. Purchased in 2015.

© Andrew Hodgson

Yellow dusty Greenockite on Sphalerite from Big Chief Mine.

Label states "Black botryoidal XLS w/few Strunzite straw colored acicular XLS." Purchased 2023.

Yellow-brown, elongated whitmoreite crystals on matrix. Rolf Luetcke specimen and photo.

Very small yellow stewartite crystals. Ex Dan Behnke and Keith Williams.

Pale orange crystals of hureaulite with blackish crystals of rockbridgeite. Ex Jocelyn Thornton collection. 5MP Chinese unbranded CMOS camera with bellows and Nikon 4X Plan Achromatic Objective Lens. Processed with Zerene stacker DMap and post stacking clean-up with Faststone and PhotoScopeX. Collection and photograph of Rod Martin.

© RJ Martin

Greenockite - anonymous handwritten label.

© Christopher O'Neill