Dave Barthelmy's Image Gallery

Labradorite: (Ca,Na)(Si,Al)4O8  
Plagioclase: (Na,Ca)(Si,Al)4O8

Comments: Dual view of a cleavage fragment of labradorite showing the multi-colored labradorescence (schiller effect) and the same area viewed without the color. The color is due to optical interference on Bøggild exsolution lamellae.
Location: Ihosy, Betroka district, Toliara Province, Madagascar. Scale: Picture size 3x3 cm.
© Dave Barthelmy

Lanarkite: Pb2(SO4)O

Comments: Cleaved crystals of greenish beige lanakite on matrix.
Location: Leadhills, Scotland. Scale: Picture size 2 cm.
© Dave Barthelmy

Lead: Pb

Comments: Irregular mass of native lead from a lead-zinc-silver ore deposit.
Location: Broken Hill, NSW, Australia. Scale: 8 cm across.
© Dave Barthelmy

Livingstonite: HgSb4S8

Comments: Dark brown, acicular-columnar crystals of livingstonite in anhydrite.
Location: Guerrero, Mexico. Scale: 2x3 cm.
© Dave Barthelmy

Lizardite: Mg3Si2O5(OH)4

Comments: Lizardite pseudomorphously replacing olivine.
Location: Snarum, Norway. Scale: 2x2 cm.
© Dave Barthelmy

Magnesiotaaffeite-2N2S: Mg3Al8BeO16

Comments: Faucetted purple magnesiotaaffeite. These specimens are very rare and un-cut samples ever rarer..
Location: Ceylon gem gravels, Ratnapura, Sri Lanka. Scale: See Image.
© Dave Barthelmy

Malachite: Cu2(CO3)(OH)2  
Azurite: Cu3(CO3)2(OH)2

Comments: Dark blue stubby pyramidal azurite crystals and green botryoidal-shaped radial aggregates of malachite.
Location: Nevada Lode Mine, San Juan Co., Utah, USA. Scale: 4 cm.
© Dave Barthelmy

Meneghinite: Pb13CuSb7S24

Comments: Black, acicular crystals of meneghinite on matrix.
Location: Bottino Mine, Tuscany, Italy. Scale: 1x1 cm.
© Dave Barthelmy

Millerite: NiS

Comments: Dense tuft of hair-like millerite crystals.
Location: Kerr-Addison mine, Timmons, Ontario, Canada. Scale: Tuft height 5 cm.
© Dave Barthelmy

Minrecordite: CaZn(CO3)2  
Wendwilsonite: Ca2(Mg,Co)(AsO4)2·2(H2O)

Comments: Wendell Wilson, publisher, editor-in-chief of the Mineralogical Record, and the person whom wendwilsonite was named after, kindly provided the mineral name pronunciations for minrecordite and wendwilsonite.
Location: Tucson Convention Center, 50th Tucson Gem and Mineral Show, February 14, 2004. Scale: NA.
© Dave Barthelmy

Moeloite: Pb6Sb6S14(S3)

Comments: Dark gray, metallic grains of moelite on white dolomite.
Location: Cava Ceragiola, Seravezza, Lucca, Italy. Scale: Picture size 2 cm.
© Dave Barthelmy

Mullite: Al(4+2x)Si(2-2x)O(10-x) where x =0.17 to 0.59

Comments: Surface of a kaolinite stratum altered to white mullite by a prehistoric coal-seam-fire..
Location: Mt. Wingen (Burning Mountain), NSW, Australia. Scale: Picture size 6x4 cm.
© Dave Barthelmy

Muscovite: KAl2(Si3Al)O10(OH,F)2

Comments: Pseudo-hexagonal crystalline aggregate of muscovite.
Location: Conselheiro Pena, Minas Gerais, Brazil. Scale: Crystal size 2 cm.
© Dave Barthelmy

Nahcolite: NaHCO3  
Trona: Na3(CO3)(HCO3)·2(H2O)

Comments: Massive, coarse-grained Trona from a drill core of the upper mixed-layer Saltbed. White areas are nahcolite alteration.
Location: Searles Lake, San Bernardino County, California, USA. Scale: 12 x 15 cm.
© Dave Barthelmy

Nikischerite: NaFe++6Al3(SO4)2(OH)18(H2O)12

Comments: Tony Nikischer, Chairman of the Board of The Hudson Institute of Mineralogy, president of Excalibur Mineral Corporation, and the person whom nikischerite is named for, kindly provided the pronunciation of the mineral nikischerite.
Location: Executive Inn hotel, Room 128, Tucson, Feburary 9, 2004. Scale: NA.
© Dave Barthelmy

Northupite: Na3Mg(CO3)2Cl

Comments: Single octahedron of Northupite.
Location: Searles Lake, San Bernardino County, California, USA. Scale: Grain size 8 mm.
© Dave Barthelmy

Parachrysotile: Mg3Si2O5(OH)4

Comments: Asbestos fibers of greenish parachrysotile.
Location: Timmins, Ontario, Canada. Scale: 8x10 cm.
© Dave Barthelmy

Pargasite: NaCa2(Mg,Fe++)4Al(Si6Al2)O22(OH)2

Comments: Lime green, prismatic crystals of pargasite in matrix.
Location: Luc Yen, Vietnam. Scale: 12x10 cm.
© Dave Barthelmy

Penikisite: BaMg2Al2(PO4)3(OH)3  
Jagowerite: BaAl2(PO4)2(OH)2

Comments: Light green crystal of jagowerite intergrown with darker green penikisite in a tetrahedrite (black) and white quartz matrix.
Location: From quartz veins cutting clays 26 km N of Hess River, Yukon Territory, Canada. Scale: Sample size 2x1 cm.
© Dave Barthelmy

Plagioclase: (Na,Ca)(Si,Al)4O8  
Labradorite: (Ca,Na)(Si,Al)4O8

Comments: Dual view of a cleavage fragment of labradorite showing the multi-colored labradorescence (schiller effect) and the same area viewed without the color. The color is due to optical interference on Bøggild exsolution lamellae.
Location: Ihosy, Betroka district, Toliara Province, Madagascar. Scale: Picture size 3x3 cm.
© Dave Barthelmy