Studies using the optical absorption spectra show that satterlyite has similar features to different iron bearing minerals with Fe ( III ) and Fe ( II ) impurities.
12.
It is a rare secondary mineral formed by hydration or alteration of the primary nickel and iron bearing minerals, chromite, pentlandite, pyrrhotite, and millerite, during the serpentinization of ultramafic rocks.
13.
The San Pedro and Furada Formations are up to 300 metres thick and consists of shale and iron bearing sandstone interbedded, These are from Wenlock Ludlow and Lower Gedinian times.
14.
A calcium iron bearing variant, named braunite II ( formula : Ca ( Mn 3 +, Fe 3 + ) 14 SiO 24 ), was discovered and described in 1967 from Kalahari, Cape Province, South Africa.
15.
The existing bedrock includes very ancient Archean gneiss, metamorphic beds interspersed with granite intrusions created during the Caledonian mountain building period ( the Caledonian orogeny ), commercially important coal, oil and iron bearing carboniferousdeposits and the remains of substantial Paleogene volcanoes.
16.
The existing bedrock includes very ancient Archean gneiss, metamorphic beds interspersed with granite intrusions created during the Caledonian mountain building period ( the Caledonian orogeny ), commercially important coal, oil and iron bearing carboniferous deposits and the remains of substantial Paleogene volcanoes.
17.
The diagonals and verticals are connected to the upper and lower chords by means of cast-iron bearing blocks . " Those bearing blocks are " embossed with the name of their manufacturer,'R . Comins, Troy, N . Y .,'" and, although the timber used is local, the bridge " appears to be a rare surviving example of this type of prefabricated nineteenth-century bridge construction ."
