Pseudomorphs and Casts Minerals Gallery M&W Minerals

Pseudomorphs and Casts Gallery

On this gallery, are gathered all the specimens on this website which are considered pseudomorphs. A pseudomorph is a mineral or mineral compound which is in an atypical form, which has resulted from a substitution process in which the appearance and dimensions of one mineral have been retained, but the original mineral is replaced by another. The name literally means "false form". There are essentially 3 kinds of pseudmorphs which are the following:

Substitution Pseudomorphs: In these specimens, one mineral has been completely chemically substituted by another mineral. The shape of the original mineral is retained, but color, hardness, and density are usually different (and often luster).

Alteration Pseudomorphs: In these specimens, only a partial substitution has occurred. This leads to a specimen with a layer of the new mineral with an interior of the original mineral with the shape of the original mineral.

Perimorphs: In these specimens, one mineral has been coated by another and the original has dissolved. This usually leads to a specimen with a mix of surfaces both of the new mineral and the surfaces of the dissolved mineral. A gray area is where this

dissolution is not natural. A case in point, Michigan Copper specimens are often found as casts after Calcite. In some cases, the dissolution has occurred due to acidic natural solutions but in other cases the Calcite has been purposely etched out with acid. Sometimes it is difficult to differentiate between the two.

Casts: In these specimens, a mineral has formed but it's shape has been determined by the environment in which it formed. Two examples are geodes and Michigan Copper Skulls and Amygdules.

minerals in alphabetical order by first letter only
(this is the primary mineral of the specimen - the pseudomorph may be a secondary mineral)

click on the title link or photo to proceed to a specimen's page

A

#1214 Antlerite

Chuquicamata Mine, Chuquicamata District, Calama, El Loa Province, Antofagasta Region, Chile
Cu₃(SO₄)(OH)₄
3.6 x 3.8 x 1.1 cm
SOLD

#117 Lilac Amethyst cast after Anhydrite

Planalto, Alto Uruguai region, Rio Grande do Sul, Brazil
10 x 9.1 x 5.9 cm
$75

B

#1281 Binghamite with Silkstone, Goethite, and Hematite

Rabbit Lake mine, Cuyuna North Range, Crow Wing Co., Minnesota, USA
8.2 x 7 x 1.8 cm
$20

#1272 Baculites

Pierre Shale, South Dakota, USA
Cretaceous Period
14 x 4.4 x 3.2 cm
$70

#150 Birnessite pseudomorph after Serandite

Mont Saint-Hilaire, Rouville RCM, Monteregie, Quebec, Canada
Na₄Mn₁₄O₂₇·9H₂O
5 x 3.5 x 2.5 cm
$175

C

#1292 Calcite psuedomorph after Barite, Chalcopyrite Zacatecas, Mexico 7.2 x 6.2 x 4.3 cm $50	#1072 Chamosite pseudomorph after Garnet Michigamme Mine, Marquette County, Michigan, USA 7 x 5.5 x 5.3 cm $40	#1004 Chrysocolla pseudomorph after Brochantite Morenci, Greenlee Co., Arizona, USA 8.4 x 5 x 2 cm $35
#946 Calcite pseudomorph after Ikaite Carter Creek, North Slope Borough, Alaska, USA 8.5 x 3 x 2.5 cm $40	#945 Calcite pseudomorph after Ikaite Carter Creek, North Slope Borough, Alaska, USA 4.8 x 1.5 x 0.8 cm $20	#598 Copper Amygdules Copper Falls Mine, Copper Falls, near Eagle Harbor, Keweenaw County, Michigan, USA 4.7 x 3.3 x 2.2 cm $40
#282 Copper Skull Lake Superior Copper District, Michigan, USA 10.2 x 6.3 x 4.6 cm $200	#235 Calcite Hollow Hemisphere Tsumeb, Namibia 6 x 5 x 3 cm $100

G

#225 Goethite

Chihuahua, Mexico
6 x 5.5 x 3.7 cm
$45

H

#1192 Halite Pseudomorph after Gypsum

Salt deposit, Mulhouse, Haut-Rhin, Alsace, France
2.4 x 3.7 x 2.5 cm
$25

#1113 Hematite pseudomorph after Pyrite

Graves Mountain, Lincoln County, Georgia
9.1 x 6 x 4.5 cm
$75

M

#286 Muscovite pseudomorph after Spodumene

Ouro Fino Mine, Coronel Murta, Minas Gerais, Brazil
4.3 x 3.2 x 2.5 cm
$25

#147 Muscovite replacing Lepidolite

Barro do Salinas, Minas Gerais, Brazil
4.3 x 3.2 x 2,5 cm
$50

P

#1247 Prehnite Cast after Laumonite Lane & Sons Traprock quarries, Westfield, Hampden County, Massachusetts, USA Repaired 6.1 x 1.9 x 1.5 cm $45	#1076 Petoskey Stone (Hexagonaria percarinata) Northern Lower Penninsula, Michigan, USA State Stone of Michigan 5.4 x 5.3 x 2.7 cm $15	#1024 Prehnite pseudomorphs after Laumonite Lane & Sons Traprock quarries, Westfield, Hampden County, Massachusetts, USA 9.1 x 6.2 x 6.1 cm $85
#338 Pyrite pseudomorph after Pyrrhotite Zacatecas, Mexico 8 x 5.7 x 4 cm $50

Q

#978 Druzy Quartz over Chrysocolla Stalactites 1990 foot level, Ray Mine, Scott Mountain area, Mineral Creek District, Dripping Spring Mts, Pinal Co., Arizona, USA Ex. Sam Elbin 4 x 4 x 2.4 cm longest stalactite is 1.5 cm $250	#432 Quartz and Hematite pseudomorph after Epidote Bessemer Ridge, Green Mountain, North Bend, King County, Washington 7 x 2.1 x 1.5 cm $55	#280 Quartz pseudomorph after Anhydrite with Calcite Saltinho, Rio Grande do Sul, Brazil 6 x 3.9 x 4.1 cm $90
#275 Quartz cast after Anhydrite Upper New Street Quarry, West Paterson, Passaic County, New Jersey Ex. Ernie Schlichter 8 x 5.5 x 4 cm $35