BESSEMER RIDGE
near North Bend, King County, Washington, USA



GEOLOGY
Skarn (tactite) - Metasomatism (chemical alteration of rock by high temperature fluids) of Tertiary marine sedimentary rock by the intrusion of magma associated with the Snoqualmie batholith (25 Mya).

MINERALS
*Andradite-
Ca3Fe3+2(SiO4)3 - Crude dark-red to black crystals less than 1 inch in grossularite matrix. Some crystals exhibit strong zoning (dark Fe-rich andradite cores with light-green Al-rich grossular rims).
*Hematite-
Fe2O3 - Occurs as pseudomorphs after an undetermined mineral (epidote, pyroxene and/or scapolite).
*Quartz-
SiO2 - Occurs as gemmy mm-scale crystals commonly coating the above described pseudomorphs.

* photographed
 
ANDRADITE Garnet
 
QUARTZ, HEMATITE
pseudomorph