Thermal modification of hematite-ilmenite intergrowths in the …
We propose a mechanism, similar to that of Kontny and Dietl (2001), in which reheating has driven T-f O2 conditions across the hematite-magnetite buffer to lower f O2 resulting in the reduction of hematite. Higher temperatures also enhanced oxidation in ilmenite.
اقرأ أكثرGeochemistry of magnetite and hematite from
Petrography and mineral chemical data indicate that rounded hematite grains from the Thelon Formation quartz arenite at Kiggavik (Fig. 3E–F) are detrital, and mainly sourced by the Kiggavik igneous basement, whereas a proportion of hematite grains could have formed by in situ replacement of detrital magnetite and ilmenite grains as a result ...
اقرأ أكثرLamellar magnetism in the haematite–ilmenite series as …
Haemo-ilmenite samples without coexisting magnetite have natural remanent magnetization to magnetic saturation ratios of only ∼ 2.5%, showing that the haematite …
اقرأ أكثرPreliminary report on magnetic susceptibility measurements …
The occurrence of hematite and ilmenite may be due to the alteration of magnetite. Keywords – magnetic susceptibility, paramagnetic, magnetite, Zaria, granite,
اقرأ أكثرMagnetic properties of ilmenite, hematite and oilsand …
The highest magnetic susceptibility was obtained when the peak intensity ratio between hematite and ilmenite was between 1.5 and 3.5. 4. Reduction roasting of the ilmenite …
اقرأ أكثرMagnetic properties of ilmenite-hematite single crystals from …
The two groups closest to the Quottoon Pluton contain magnetite within hematite and ilmenite lamellae. Reheating of the Ecstall pluton led to an increase in coercivity and magnetization, as well as to development of mixed phase hysteresis. These results indicate that shallow paleomagnetic directions from the western Ecstall pluton are not ...
اقرأ أكثرNature and origin of lamellar magnetism in the hematite-ilmenite …
Rock-magnetic experiments suggest remanence is thermally locked to the antiferromagnetism of the hematite component of the intergrowths, yet is stronger than can be explained by canted antiferromagnetic (CAF) hematite or coexisting paramagnetic (PM) Fe-Ti-ordered (R3̅) ilmenite alone. In alternating field demagnetization to 100 mT, many ...
اقرأ أكثرMagnetic properties of ilmenite‐hematite single crystals from …
Ternary plot of the hematite-ilmenite-magnetite composition of oxide grains based on assumptions and field-cooled remanence experiments. Group 1 (blue squares) has the least variability and is dominated by hematite. Groups 2 (green triangles) and 3 (red circles) have greater variability, with more magnetite than group 1. ...
اقرأ أكثرFerromagnetism and exchange bias in compressed ilmenite-hematite …
Earth's magnetic anomalies are commonly attributed to the presence of magnetite, hematite, titanomagnetite, and pyrrhotite minerals. Magnetite (Fe 3 O 4) shows strong ferromagnetism, and hematite (α-Fe 2 O 3) shows antiferromagnetism with superimposed weak ferromagnetism ().Ilmenite (FeTiO 3) is a common mineral in nature and usually shows …
اقرأ أكثرIlmenite – Virtual Museum of Molecules and Minerals
Ilmenite is an opaque accessory mineral in a wide range of igneous and metamorphic rocks, especially gabbroic varieties, where it is associated with hematite and magnetite as lattice-type intergrowths, and other minerals such as plagioclase and hornblende. Masses of ilmenite were found in several emery mines in the USA, Norway, Canada and Russia.
اقرأ أكثرIlmenite: An ore of titanium | Uses and Properties
With just a glance it can easily be confused with hematite and magnetite. The differentiation is easy. Hematite has a red streak, while ilmenite has a black streak. Magnetite is strongly magnetic, while ilmenite is not magnetic. Occasionally ilmenite is weakly magnetic, possibly from small amounts of included magnetite.
اقرأ أكثرIlmenite: An ore of titanium | Uses and Properties
With just a glance it can easily be confused with hematite and magnetite. The differentiation is easy. Hematite has a red streak, while ilmenite has a black streak. Magnetite is strongly magnetic, while ilmenite is not magnetic. …
اقرأ أكثرLamellar magnetism in the haematite–ilmenite series …
The role of hematite-ilmenite solid solution in the production of magnetic anomalies in ground and satellite-based data. Tectonophysics 347, 166–177 (2002) ADS Article Google Scholar
اقرأ أكثرMagnetite | Common Minerals
Ilmenite is a dense, black metallic mineral that, when rubbed across a rough hard surface, exhibits a black streak similar to that of magnetite. As ilmenite is not magnetic, a magnet …
اقرأ أكثرChemical and petrographic characterization of ilmenite …
determined by Wilson et al. (1996), was from hematite-rich ilmenite with minor end-member magnetite to hematite-poor ilmenite with titanomagnetite, a trend indicating progressive diminution of Fe2O3. This trend was accompanied by decreasing MgO and Cr2O3, and by gradually increasing V2O3 to the point where magnetite
اقرأ أكثرThe role of hematite–ilmenite solid solution in the …
Throughout this report, the terms hemo-ilmenite and ilmeno-hematite are adopted for unmixed grains that are rich in ilmenite and hematite content, respectively. In addition, titanohematite and ferrian ilmenite are used for the individual exsolved pha-ses. Fig. 1. Example of magnetic anomaly generated entirely by the remanent magnetism of ...
اقرأ أكثرHigh-temperature creep of magnetite and ilmenite single crystals
Magnetite and ilmenite often occur together in oxide-rich zones of highly differentiated igneous rocks (Ashwal 1982), while magnetite and hematite may occur together in banded iron formations where fluid-present deformation facilitates oxidative transformation of magnetite to secondary hematite (Lagoeiro 1998). At oxidizing conditions near the ...
اقرأ أكثرThe role of hematite–ilmenite solid solution in the production …
Throughout this report, the terms hemo-ilmenite and ilmeno-hematite are adopted for unmixed grains that are rich in ilmenite and hematite content, respectively. In addition, titanohematite …
اقرأ أكثرIlmenite, magnetite, hematite, and copper in lavas of the …
January 1, 1951. The opaque minerals in ten lava flows of the Keweenawan series of Michigan were studied microscopically by the writer. The basaltic lavas, which range in thickness from …
اقرأ أكثرIlmenite: An ore of titanium | Uses and Properties
With just a glance it can easily be confused with hematite and magnetite. The differentiation is easy. Hematite has a red streak, while ilmenite has a black streak. Magnetite is strongly …
اقرأ أكثرMagnetic properties of ilmenite‐hematite single crystals
Group 3 populates the ternary space between groups 1 and 2, and has hematite‐ilmenite‐magnetite compositions that could be formed by oxidizing the magnetite in group 2 samples back to hematite. 9 Ternary plot of the hematite‐ilmenite‐magnetite composition of oxide grains based on assumptions and field‐cooled remanence experiments.
اقرأ أكثرMicrostructure and magnetism in the ilmenite-hematite solid solution: A
The energetics of magnetic and cation ordering have been modeled using an atomistic approach based on empirical exchange interaction parameters. The model has been applied to the study of magnetic and cation ordering in the ilmenite-hematite solid solution via Monte Carlo simulations, providing new insight into the effect of nanoscale ...
اقرأ أكثرIlmenite, magnetite, hematite, and copper in lavas of the …
The basaltic lavas, which range in thickness from 100 to 1,400 feet, contain ilmenite, magnetite, hematite, intergrowths of magnetite-ilmenite and ilmenite-hematite, copper sulfides, native …
اقرأ أكثرMagnetic Clusters in Ilmenite-Hematite Solid Solutions
PHYSICAL REVIEW B 81, 224423 ͑2010͒ Magnetic clusters in ilmenite-hematite solid solutions C. Frandsen,1,* B. P. Burton,2 H. K. Rasmussen,1 S. A.
اقرأ أكثرIlmenite of Black Sand Deposits of Visakhapatnam …
Ilmenite-Polished mounts of separated grains have revealed a variety of exsolution intergrowth textures between ilmenite and titanhematite, similar to those described from Karaikal coast, Tamil Nadu4• Ilmenite) Fig.2-Dash-like titan hematite exsolved from ilmenite (SEM, x 980). Fig. 3-Plate-shaped coarse ilmenite (higher relieOexsolved from
اقرأ أكثرRe: Dark, metallic mystery mineral
The linear texture of the last piece (I suspect the bottom as it formed) is consistent with crystallization, not with crystallization of magnetite, but perhaps with hematite. It's really hard for me to imagine a scenario to create a natural layer in a sedimentary environment, unless it's sort of a bog iron, which could be a mixture of iron ...
اقرأ أكثرILMENITE-HEMATITE-MAGNETITE RELATIONS IN
necessary to bring out the hematite-ilmenite relations. Every patch of hematite contains minute exsolution lamellae of ilmenite, which com-monly lie in one, two or three directions within …
اقرأ أكثرRe: Dark, metallic mystery mineral
From what I understand it's made up completely of sedimentary rock, which makes the mineral find all the more mysterious to me because it appears to me that it's of magmatic …
اقرأ أكثرIlmenite-hematite-magnetite relations in some emery ores
Close mobile search navigation. Article navigation. Volume 24, Number 3
اقرأ أكثرMagnetite-rutile symplectite derived from ilmenite-hematite …
According to Tan et al. (2015), the magnetite-rutile symplectite hosted by ilmenite from the Xinjie Fe-Ti oxide-bearing mafic-ultramafic layered intrusion (SW China) was formed by the subsolidus ...
اقرأ أكثرILMENITE-HEMATITE-MAGNETITE RELATIONS IN
magnetite-hematite boundaries, showing that much of the hematite now present crystal-lized originally as hematite, and is thus not a later repLacement product of magnetite. ... ilmenite-hematite solid solution was in this case exceedingly rich in ilmenite (Ti) and poor in hematite (Fe). Exsolution oJ hemati.te from corunilwm
اقرأ أكثرIlmenite, magnetite, hematite, and copper in lavas of the …
The earlier group includes magnetite, ilmenite, magnetite-ilmenite and ilmenite-hematite intergrowths, copper sulfides, and native copper. The later group includes hematite, native copper, chalcocite, pyrite, chlorite, and sphene. The second-generation minerals formed by the action of volatiles escaping from the lavas. The ratio of Ti to total ...
اقرأ أكثرILMENITE-HEMATITE-MAGNETITE RELATIONS in SOME EMERY …
Some replacement of magnetite by hematite is noted, but only a minor percentage of the total hematite present has formed in this manner. Ilmenite of one age often exsolves parallel to trvo crystallographic directions within hematite. In addition, trvo readily distinguishable ages of exsolution ilmenite in hematite are often observed.
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