 | near North Bend, King County, Washington, USA |
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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
| 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). | |
| Fe2O3 - Occurs as pseudomorphs after an undetermined mineral (epidote, pyroxene and/or scapolite). | |
| SiO2 - Occurs as gemmy mm-scale crystals commonly coating the above described pseudomorphs. |
* photographed
ANDRADITE Garnet |
QUARTZ, HEMATITE pseudomorph |
QUARTZ, HEMATITE pseudomorph |