Peter Megaw's Photo Gallery

PG7-1V2Goethite α-Fe³⁺O(OH) , Gypsum CaSO₄·2H₂O , Calcite CaCO₃

Potosí Mine, Francisco Portillo, West Camp, Santa Eulalia Mining District, Aquiles Serdán Municipality, Chihuahua, Mexico

Dimensions: 18 cm x 20 cm x 10 cm

Goethite epimorph after gypsum with partial coating of calcite. Gypsum is completely gone leaving hollow tubes with perfect imprints of the striations of the original gypsum. From Level 2 of the Potosi Mine in the shrinkage cavity developed at the top of the Chorro Chimney. The gypsum was probably a hypogene product deposited late in ore mineralization that got coated by goethite during oxidation.
This specimen is widely known as "The Shipwreck".

LR7-H6YStrontianite SrCO₃ , Fluorite CaF₂ , Celestine SrSO₄

Tule Mine, Melchor Múzquiz, Múzquiz Municipality, Coahuila, Mexico

Dimensions: 7 cm x 5 cm x 3.5 cm
Largest Crystal Size: 3 mm

Sprays of white, elongate strontianite encrusting classic fluorite on Celestine from this famous mine. Longest strontianite crystals are 3mm, most much smaller. Not sure why we don't see more strontianite identified from here...perhaps it's removed by the miners? From a lot purchased in Mapimi in the mid 80s.

WQJ-UEMSmithsonite ZnCO₃

Ojuela Mine, Mapimí, Mapimí Municipality, Durango, Mexico

Dimensions: 4 cm x 4 cm x 2 cm

1.2 cm stalactite of small lustrous brown smithsonite crystals (in current orientation) in vug lined with similar crystals. From a small batch of specimens mined recently. All specimens I've seen so far show the same stalactitic growth

YNA-N3EWulfenite Pb(MoO₄)

Red Cloud Mine, Silver Mining District, La Paz County, Arizona, USA

Dimensions: 6 cm x 6 cm x 3 cm
Largest Crystal Size: 1.5 cm

Beautifully perched single crystal on matrix...

HY7-CHJOlivenite Cu₂(AsO₄)(OH) , Goethite α-Fe³⁺O(OH)

Milpillas Mine, Milpillas, Santa Cruz Municipality, Sonora, Mexico

Dimensions: 4 cm x 2 cm
Largest Crystal Size: 3 cm

Sharp doubly terminated olivenite crystals

TL5-P7AAndradite Ca₃Fe³⁺₂(SiO₄)₃

Ojos Españoles Mine, General Lázaro Cárdenas, Julimes Municipality, Chihuahua, Mexico

Dimensions: 5 cm x 4 cm x 3 cm

Sharp lustrous miniature...gift of Ela Fenn

384-1XNAzurite Cu₃(CO₃)₂(OH)₂ , Malachite Cu₂(CO₃)(OH)₂

Milpillas Mine, Milpillas, Santa Cruz Municipality, Sonora, Mexico

Dimensions: 14 cm x 10 cm x 5 cm

Great example of azurite on bed of botryoidal malachite from Tolvas Duales. Figured in MR Milpillas issue

CW2-DMFAzurite Cu₃(CO₃)₂(OH)₂ , Dickite Al₂(Si₂O₅)(OH)₄

Milpillas Mine, Milpillas, Santa Cruz Municipality, Sonora, Mexico

Dimensions: 10 mm x 8 mm x 4 mm

"The Bat" Unique azurite from Milpillas composed of multiple thin sheets of azurite with white dickite between them. This really lets the light shine through the azurite and bring out its color

MJ0-QC7Plancheite Cu₈(Si₈O₂₂)(OH)₄·H₂O , Malachite Cu₂(CO₃)(OH)₂ , Azurite Cu₃(CO₃)₂(OH)₂

Milpillas Mine, Milpillas, Santa Cruz Municipality, Sonora, Mexico

Dimensions: 6 cm x 4 cm x 2 cm

Malachite pseudomorph after azurite on a light blue bed of plancheite. There were very few like this. Figured in MR Milpillas issue

X5Y-320Cuprotungstite Cu₂(WO₄)(OH)₂ , Scheelite Ca(WO₄)

San Lorenzo Mine, Arizpe, Arizpe Municipality, Sonora, Mexico

Dimensions: 4 cm x 3 cm x 2 cm

Cuprotungstite in scheelite...classic piece from the Philadelphia Academy of Sciences disbursement...thanks to Bryan Lees! I have seen one other piece from this find.

Note there is some question as to the municipality the San Lorenzo lies in...Arizpe or the neighboring Huepac muncipality...Panczner lists both. The boundary was ill defined until relatively recently.