San Francisco, San Francisco County, California, USA (original) (raw)

ⓘ Antigorite

Formula: Mg3(Si2O5)(OH)4

ⓘ 'Apophyllite Group'

Formula: A B4[Si8O22]X · 8H2O

ⓘ Aragonite

Formula: CaCO3

Habit: Slender prisms

Colour: Colourless

Description: Occurs in seams in serpentine.

ⓘ Baryte

Formula: BaSO4

Habit: Tabular

Description: Occurs as crystals in seams in serpentine.

ⓘ Brucite

Formula: Mg(OH)2

Description: Occurs in cuts made by the Western Pacific railroad.

ⓘ Calcite

Formula: CaCO3

Description: Occurs as crystals exhibiting uncommon faces to several cm in size.

ⓘ Chromite

Formula: Fe2+Cr3+2O4

Description: Occurs in beach sands.

ⓘ Cinnabar

Formula: HgS

Localities:

Divisadero Street, San Francisco, San Francisco County, California, USA
Unnamed Hg occurrence [2], Twin Peaks, San Francisco, San Francisco County, California, USA
Unnamed Hg occurrence [1], Divisadero Street near McAllister Street, Lower Haight neighborhood, San Francisco, San Francisco County, California, USA

ⓘ 'Clinochrysotile'

ⓘ Coalingite

Formula: Mg10Fe3+2(OH)24[CO3] · 2H2O

Colour: Golden-brown

Description: Occurs as veinlets 1 to 2 mm thick in serpentine that is largely altered to pyroaurite.

ⓘ Datolite

Formula: CaB(SiO4)(OH)

Colour: White

Description: Occurs as glassy crystals and white veins in an altered diabase dike in serpentine.

ⓘ 'Diallage'

Description: Not specifically identified. Occurs as grains in serpentine.

ⓘ Diopside

Formula: CaMgSi2O6

Description: Not specifically identified. Occurs as grains in serpentine.

ⓘ Enstatite

Formula: Mg2Si2O6

Description: Abundant in serpentine.

ⓘ Epsomite

Formula: MgSO4 · 7H2O

Colour: White

Description: Occurs as mixtures with hexahydrite. Soft, powdery efflorescences on protected surfaces of serpentine.

ⓘ 'Fayalite-Forsterite Series'

ⓘ Gold

Formula: Au

Description: Placer material. Occurs in black sands.

ⓘ Gyrolite

Formula: NaCa16Si23AlO60(OH)8 · 14H2O

Description: Occurs as spherical or massive with apophyllite; platy or plumose aggregates replacing wall rock in fissures of basalt.

ⓘ Hexahydrite

Formula: MgSO4 · 6H2O

Colour: White

Description: Occurs as mixtures with epsomite. Soft, powdery efflorescences on protected surfaces of serpentine.

ⓘ Hydromagnesite

Formula: Mg5(CO3)4(OH)2 · 4H2O

Localities:

Market Street near Guerrero, San Francisco, San Francisco County, California, USA
Marshall Beach, Fort Point, San Francisco, San Francisco County, California, USA
Fort Point, San Francisco, San Francisco County, California, USA

ⓘ Idrialite

Formula: C22H14

ⓘ Lizardite

Formula: Mg3(Si2O5)(OH)4

ⓘ Magnesite

Formula: MgCO3

Description: Occurs as seams in serpentine.

ⓘ Mercury

Formula: Hg

Localities:

Unnamed Hg occurrence [2], Twin Peaks, San Francisco, San Francisco County, California, USA
Unnamed Hg occurrence [1], Divisadero Street near McAllister Street, Lower Haight neighborhood, San Francisco, San Francisco County, California, USA

ⓘ Nesquehonite

Formula: MgCO3 · 3H2O

Colour: White

Description: Soft surface efflorescences in moist places in serpentine.

ⓘ Nontronite

Formula: Na0.3Fe2((Si,Al)4O10)(OH)2 · nH2O

Colour: Brown

Description: Occurs as crumbly veins 2.5 to 3.0 cm thick in some serpentines.

ⓘ Opal

Formula: SiO2 · nH2O

Colour: colorless

Description: Thin layers of botryoidal colorless opal in crevices of serpentinites.

ⓘ 'Orthochrysotile'

ⓘ Pectolite

Formula: NaCa2Si3O8(OH)

Description: Occurs as veins of fibrous material in an altered dike that intersects serpentine.

ⓘ Pyroaurite

Formula: Mg6Fe3+2(OH)16[CO3] · 4H2O

ⓘ 'Pyroaurite-2H'

Formula: Mg6Fe3+2(OH)16(CO3) · 4H2O

Description: Occurws as thin coatings with hydromagnesite on fractures in serpentine.

ⓘ Quartz

Formula: SiO2

Localities:

Fort Point, San Francisco, San Francisco County, California, USA
United States Mint site, Duboce Street near Market Street, San Francisco, San Francisco County, California, USA
Divisadero Street, San Francisco, San Francisco County, California, USA
San Francisco, San Francisco County, California, USA
Lands End Station area, San Francisco, San Francisco County, California, USA

Description: Occurs as pseudomorphs after apophyllite.

ⓘ Quartz var. Chalcedony

Formula: SiO2

Description: Occurs as veins in serpentine.

ⓘ 'Serpentine Subgroup'

Formula: D3[Si2O5](OH)4

Localities:

Fort Point, San Francisco, San Francisco County, California, USA
Army Street, San Francisco, San Francisco County, California, USA
United States Mint site, Duboce Street near Market Street, San Francisco, San Francisco County, California, USA

ⓘ Wollastonite

Formula: Ca3(Si3O9)

ⓘ Xonotlite

Formula: Ca6(Si6O17)(OH)2

Localities:

Army Street, San Francisco, San Francisco County, California, USA
Marshall Beach, Fort Point, San Francisco, San Francisco County, California, USA
San Francisco, San Francisco County, California, USA

Description: Occurs in veins in serpentine.