A monoclinic mineral, NaCaFe(Fe,Mn)2 (PO4 )3 ;
alluaudite group; forms a series with alluaudite; in granite pegmatites.
a. Dolomite having up to 20% of magnesium replaced by iron or manganese.
b. A mineral composition intermediate between those of dolomite and
ankerite.
See:ceylonite
A hypothetical composition, (Mg,Fe)3 Si2 O5 (OH) (sub
4) , used to describe chlorite compositions; intermediate to antigorite
and greenalite.
A boron iron alloy containing 12% to 14% boron. USBM, 7; USBM, 6
An orthorhombic mineral, (Fe,Mg)Al2 Si2 O6 (OH) (sub
4) ; forms series with carpholite and magnesiocarpholite; dark green; in
quartz veins near Tomata, Celebes Island, Indonesia.
An alloy of iron and chromium. Pryor, 3
See:copiapite
A monoclinic mineral, Na3 (Fe2+ ,Mg)4 AlSi8
O22 (OH)2 ; amphibole group; has Mg/(Mg+Fe2+ ) = 0
to 0.49; forms a series with eckermannite.
A monoclinic mineral, NaCa2 (Fe,Mg)5 [Si7 AlO (sub
22) ](OH)2 ; amphibole group; has Mg/(Mg+Fe) = 0 to 0.49; forms a
series with edenite.
Spontaneous electrical polarization with all dipoles in the same
direction. The polarity can be reversed by an external electrical field.
Van Vlack
See:barbosalite
A gabbro in which the pyroxene or olivine, or both, are exceptionally high
in iron.
A monoclinic mineral, FeSO4 .6H2 O ; hexahydrite group;
transparent; forms at Vesuvius, Italy, as fine acicular crystals that are
unstable under normal atmospheric conditions.
A mineral in the olivine series composed of 70% to 90% fayalite and 30% to
10% forsterite.
See:ferrosilite
Black iron slag, said to be satisfactory for fashioning into gemstones.
Containing iron and magnesium. Applied to certain dark silicate minerals,
esp. amphibole, pyroxene, biotite, and olivine.
Any mineral having a considerable portion of iron and magnesium in its
composition. CF:ferrous mineral
a. Material that in general exhibits the phenomena of hysteresis and
saturation and whose permeability is dependent on the magnetizing force.
Microscopically, the elementary magnets are aligned parallel in volumes
called domains. The unmagnetized condition of a ferromagnetic material
results from the overall neutralization of the magnetization of the
domains to produce zero external magnetization. ASM, 1
b. The three substances, iron, nickel, and cobalt, are so considerably
more magnetic than any other substances that they are grouped by
themselves; they are termed ferromagnetic.
a. Spontaneous magnetic orientation of all magnetic moments in the same
direction. The orientation can be reversed by an external magnetic field.
Van Vlack
b. Strong magnetic susceptibility caused by overlap of adjacent d
orbitals; e.g., iron, nickel, cobalt, and numerous alloys, both ferrous
and nonferrous. CF:antiferromagnetism; ferrimagnetism.