Metorite looking rock from Idaho desert I believe, feels like it has a slight magnetic pull, but the magnet I have (which isnt very strong) doesnt stick, extremely heavy for its size. can you help me identify.enter image description hereenter image description here

  • $\begingroup$ Stating the location from where the rock is from might help those who could answer the question $\endgroup$ – Fred Oct 12 '18 at 8:16
  • $\begingroup$ i am not able to see where the surface show sign of being melted by air friction during atmospheric entry. $\endgroup$ – trond hansen Oct 12 '18 at 8:22
  • $\begingroup$ If you have a bucket and don't mind getting the rock wet, you could try a displacement test to measure the volume. $\endgroup$ – Spencer Oct 12 '18 at 19:35
  • $\begingroup$ If you don't mind using destructive methods, can you smash it in two with a hammer and show us how it looks from the inside? $\endgroup$ – Gimelist Oct 12 '18 at 23:04
  • $\begingroup$ Please follow this guide. $\endgroup$ – gerrit Nov 2 '18 at 12:26

Based on your rock's physical appearance:

  • Most likely not a meteorite. Meteorites are typically very firm rock and dense.
  • Rock appears to somewhat friable (ability to break or run off particles using your hands).
  • It is volcanic or igneous in nature.
  • Some volcanic rocks can be slightly magnetic, basaltic rock with high iron content.
  • Brown color indicates the rock probably contains significant amount of iron oxide or iron sulfide.
  • May show visual indication of hydro-thermal alteration caused by nearby igneous intrusive or volcanic flow.
  • Idaho has a variety of igneous and volcanic rocks exposed at the surface over much of the state.

My best guess: Altered igneous rock. Might have pyrite and/or geothite in it.

A more precise identification would require:

  • Exact location in Idaho.
  • An estimate of its density. Is the rock lighter or heavier than a sandstone, limestone, or basalt of similar size.
  • Does the rock have a odor of sulfur or iron? Try getting the rock wet.
  • If you know someone with a diamond rock saw, cut an 1/2 off the bottom.
  • Take the rock to a university geology department (U of Idaho, Boise State, Idaho State) or to rock and mineral club and have someone take a look at it.

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