Gary K. Foote wrote:
It looks more like a huge hematite node. Even its crumbs are magnetic. Pieces from it are flakes, rather than 'chunks'.
Hello Gary,
I respect that you took the time to actually go see this over-hyped paperweight . This is clearly a rock of igneous origin with minor metamorphism possible. However the likely magnetic component is magnetite for the following reasons.
While it is hard to do good ids from photos, Probability-wise this is from a pegmatite which could be local or glacially transported in the same vein(pun intended) as the deposits of Balmat New York or St Lawrence County or even Quebec Canada. The mass looks like a classic actinolite-tremolite-pyroxene group composition along with about 15-20 other minerals. The three which are likely the cause of the magnetic attraction are Chromite(>2% chance) or Magnetite (>90%chance) and secondary hematite (>5%chance). If there is a talc trend (aka soapstone, greesy feel) or any iron sulfates ( brass-colored, metallic flashes aka Pyrite Group) this indicates the mass had some hydrothermal alteration and hematite could be present. In a non perfect world, I know there is some hematite in the mass-the law of probability says so but on the order of less than .001%. The law of probability also says the magnetic attraction is due to magnetite in micro crystals within the mass. Hematite is usually associated with sedimentary deposits but can be found natively in metamorphic and igneous rocks.
Actually the composition of this mass has a lot in common with minerals found in meteorites save for the hydrated silicates. The holes are likely from areas that were more hydrated and thus softer than the original pegmatite and therefore were gouged out during rough ice or stream transport--(if not actually human made).
There is a long history of mining the magnetite deposits of New England, while else where in on the east coast the desposit of iron are in the from hematite and limonite(bog iron). Be it noted that hematite is no always magnetically attracted.
In addition to magnetite, which can be truly magnetic, there are several other minerals that may be attracted to a magnet(anistrophy of magnetic susceptibility(AMS)). <http://www.galleries.com/minerals/property/magnetis.htm>
I am intrigued by the apparent attractiveness of the plant stems on your magnet--any theories?
Elton ______________________________________________ Meteorite-list mailing list Meteorite-list@meteoritecentral.com http://six.pairlist.net/mailman/listinfo/meteorite-list
