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Magnetism Test identification and geology

The magnetism test checks whether a mineral is attracted to a magnet, which indicates the presence of iron in specific oxidation states and crystal structures. Magnetite Fe₃O₄ is the most strongly magnetic common mineral and will readily cling to a standard handheld magnet. Pyrrhotite Fe₁₋ₓS displays weaker magnetism and may only be attracted to strong rare-earth magnets. A few other minerals, including some varieties of ilmenite and native iron in meteorites, are also magnetic. Magnetism in minerals arises from unpaired electrons in iron and sometimes nickel or cobalt atoms. Ferromagnetism, as seen in magnetite, involves the cooperative alignment of magnetic domains and produces the strongest response. Ferrimagnetism and paramagnetism produce weaker effects. The distinction between ferromagnetic and paramagnetic responses is diagnostically significant: if a mineral jumps to a standard ceramic magnet, it is almost certainly magnetite; if it requires a neodymium rare-earth magnet, pyrrhotite or ilmenite should be considered. This test is quick, non-destructive, and requires no consumables, making it one of the most practical field tests. A small magnet on a string can also be used in reverse: dangle the magnet near the specimen and watch for deflection, which avoids magnetizing your tools. Tips: Always carry both a ceramic and a neodymium magnet—the distinction between strong and weak magnetism is diagnostically important. Keep magnets away from electronic devices, credit cards, and compasses when not testing. Neodymium magnets are brittle and can shatter if dropped; handle with care. Crushed or powdered magnetite-bearing rock will show magnetic grains even when the bulk rock seems non-magnetic. If you suspect magnetite inclusions, try the test on a powdered sample.. Equipment: Standard ceramic ferrite magnet, neodymium rare-earth magnet for detecting weak magnetism, string or thread optional, for the dangling-magnet method . A compass can also detect strongly magnetic specimens at close range.. Procedure: 1. Hold a ceramic magnet near or touching the mineral specimen. 2. Observe whether the specimen is attracted, repelled, or unaffected. 3. If no response with the ceramic magnet, repeat with a neodymium magnet to test for weaker magnetic attraction. 4. For small grains or powdered samples, pass the magnet through or over the material and check for adherent g

Sources, scope & corrections

These authoritative resources support category-level nomenclature, terminology, identification methods, and safety. When a specimen-specific safety warning appears, the public-health source listed here directly supports that precaution. They are not line-by-line citations for every other property on this entry, and natural specimens vary.

Editorial owner
GeoMiner
Last updated
2026-03-30T15:00:37.048321+00:00
Review status
Published; not independently peer-reviewed
  • How Do Geologists Identify Minerals? — Utah Geological Survey. Practical guidance on diagnostic physical properties and identification tests.
  • Mineral ID Key — Mineralogical Society of America. Detailed test methods, repeatability guidance, and safety cautions.

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Common questions

What is the Magnetism Test used for?
The magnetism test checks whether a mineral is attracted to a magnet, which indicates the presence of iron in specific oxidation states and crystal structures. Magnetite Fe₃O₄ is the most strongly magnetic common mineral and will readily cling to a standard handheld magnet. Pyrrhotite Fe₁₋ₓS displays weaker magnetism and may only be attracted to strong rare-earth magnets. A few other minerals, including some varieties of ilmenite and native iron in meteorites, are also magnetic. Magnetism in minerals arises from unpaired electrons in iron and sometimes nickel or cobalt atoms. Ferromagnetism, as seen in magnetite, involves the cooperative alignment of magnetic domains and produces the strongest response. Ferrimagnetism and paramagnetism produce weaker effects. The distinction between ferromagnetic and paramagnetic responses is diagnostically significant: if a mineral jumps to a standard ceramic magnet, it is almost certainly magnetite; if it requires a neodymium rare-earth magnet, pyrrhotite or ilmenite should be considered. This test is quick, non-destructive, and requires no consumables, making it one of the most practical field tests. A small magnet on a string can also be used in reverse: dangle the magnet near the specimen and watch for deflection, which avoids magnetizing your tools.
How do you perform the Magnetism Test?
1. Hold a ceramic magnet near or touching the mineral specimen. 2. Observe whether the specimen is attracted, repelled, or unaffected. 3. If no response with the ceramic magnet, repeat with a neodymium magnet to test for weaker magnetic attraction. 4. For small grains or powdered samples, pass the magnet through or over the material and check for adherent grains. 5. Alternatively, tie a magnet to a string and dangle it near the specimen. Deflection of the magnet indicates magnetism in the specimen. 6. Record the strength of the response: strongly magnetic attracted to ceramic magnet , weakly magnetic only attracted to neodymium magnet , or non-magnetic. 7. If the specimen itself deflects a compass needle from more than a few centimeters away, it is strongly magnetic.
How do you interpret the Magnetism Test?
Strongly magnetic jumps to ceramic magnet = almost certainly magnetite; rarely native iron or nickel-iron meteoritic . Weakly magnetic attracted only to neodymium/rare-earth magnet = likely pyrrhotite; possibly ilmenite, chromite, or franklinite. Non-magnetic = most common minerals including hematite, pyrite, quartz, feldspars, and all carbonates. Note: some dark, iron-rich minerals may appear magnetic due to magnetite inclusions—test a clean, single-crystal fragment if possible.
What equipment is needed for the Magnetism Test?
Standard ceramic ferrite magnet, neodymium rare-earth magnet for detecting weak magnetism, string or thread optional, for the dangling-magnet method . A compass can also detect strongly magnetic specimens at close range.
What safety precautions apply to the Magnetism Test?
The listed safety level is safe.

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