Magnetic susceptibility (MS) measurements of hematite and magnetite samples from the Colorado School of Mines Geology Museum were made at 600 Hz using a Sapphire Instruments magnetic susceptibility meter with a 8.1 cm diameter coil. The instrument was borrowed from Rich Reynolds at the USGS-Denver Federal Center Office.
A scatter plot of all the measurements is shown below. The error bars represent plus or minus one standard deviation, or the 68.3% confidence interval. The magnetic susceptibility (always in SI units on this website) is normalized by the weight of the sample. Unfortunately, the density of the samples is unknown. (The museum quality samples could not be submersed in water in order to determine the volume.) Histograms of both hematite and magnetite are shown below the scatter plot. The scatter plot and histograms show the large variability of hematite's magnetic susceptibility over five orders of magnitude compared to the small variability of magnetite, where 75% of the data is constrained to one order of magnitude.
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