VERY very faint grey streaks. VERY faint. ary
On 9 May 2006 at 19:14, Bill Southern wrote: > A simple streak test will ID either.. > > Magnetite - greasy black or grey streak > > Hematite - Reddish to rust brown streak > > On unglazed porcelain. > > Bill > > --- Elton Jones <[EMAIL PROTECTED]> wrote: > > > 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 > > [email protected] > > > http://six.pairlist.net/mailman/listinfo/meteorite-list > > > > > > [EMAIL PROTECTED] > http://www.NuggetShooter.com > > > __________________________________________________ > Do You Yahoo!? > Tired of spam? Yahoo! Mail has the best spam protection around > http://mail.yahoo.com > ______________________________________________ > Meteorite-list mailing list > [email protected] > http://six.pairlist.net/mailman/listinfo/meteorite-list ______________________________________________ Meteorite-list mailing list [email protected] http://six.pairlist.net/mailman/listinfo/meteorite-list
