[meteorite-list] mafic igneous rocks

[E. L. Jones]

Virtualy all the ferro-magnesium silicates (pyroxenes, amphiboles etc) 
are by definition iron bearing. I don't think they are magneticlly 
attractive.  Magnetite, usually in very small grains, can occur in 
them.  Alteration by water can produce hematite which can be 
magnetically attractive and usually is.  I just observed a sample where 
a film of  hemitite was less than a half milimeter thick and it made my 
magnetic wand jump to it as if it were iron plate.

Elton


j.divelbiss at att.net wrote:

>Bill,
>
>I'm sure the mineral magnetite is your source of paramagmatism. Igneous rocks are often magnetite rich.
>
>Iron would also be in many other minerals...but magnetite is likely your source of attracting a magnet(paramagnetism).
>
>JD
>
>Hi all,
>
>I understand that mafic igneous rocks contain iron but does anyone know what 
>form it's in and how it's distribution is characterized? Is this iron content 
>high enough to make it magnetically attractive? I have a batch of interesting 
>wrongs that I'm trying to sort out.
>
>Best regards,Bill
>