I think this is likely to be waste metal from iron smelting, especially as it is magnetic. It's not possible to be sure from images alone though so email firstname.lastname@example.org if you'd like to arrange to bring or post it into the museum and we'll try and determine its composition.
Hello when i said magnetic. the 1mil crust on the outside is magnetic the rest is not there is no rust so it not iron it looks like silver and its as hard as steel . could it be a meteorite.
I think I can see some right angles here and there... So, galena? Compare for instance http://bertan.gipuzkoakultura.net/img/17/grandes/GALENA.jpg. It is quite heavy (I guess your object is quite heavy [I have no idea what local and obsolete units like ounces amounts to!] and, well, galena is lead sulfide after all) - the density is 7.2 - 7.6 g/cm3. According to http://www.naturalareas.naturalengland.org.uk/science/natural/profiles%5CnaProfile2.pdf galena can be found in Northumberland (at least in the Cheviot Hills area) and on http://www.archive.org/stream/leadores00halluoft/leadores00halluoft_djvu.txt it says "The chief mining centres are situated in the neighbourhood of Hexham, Northumberland ; Upper Teesdale and Weardale, Durham  ; Alston Moor, Cumberland   ; Brough and Dufton Fell, Westmorland ; and Upper Swaledale, Arkendale and Wensleydale, Yorkshire; but most of the mines are now derelict, though in past years they yielded a very large part of the British output of lead ore." ("lead ore" = galena)
The magnetic part can perhaps be magnetite (it has to be something that is magnetic), but more probably it is pyrrhotite (a.k.a. pyrrhotine, magnetic pyrite), the only other common magnetic mineral (and, like galena, it is a sulfide). Both can be associated with galena.
A small addendum.
On http://www.northumberlandnationalpark.org.uk/__data/assets/pdf_file/0005/147524/geodiversity_audit_hi.pdf (p. 76) it says: "The iron sulphides pyrite and pyrrhotite, along with galena and sphalerite, are locally common as thin coatings on joints in the Whin Sill at Barrasford Quarry. Pyrrhotite is also common in contact-altered ironstone nodules at this locality. A few well-crystallised examples of galena have also been recovered from a veinlet adjacent to the contact of the Whin Sill with lower Carboniferous rocks at Divethill Quarry."
I keep on replying to myself...
On http://sv.wikipedia.org/wiki/Fil:Galena-246433.jpg there is a photo of galena from Co Durham. Note that this small lump weighs 2.2 kg!
On http://www.curriehj.freeserve.co.uk/nentgal1.jpg there is galena from Cumbria. The accompanying text on the page (http://www.curriehj.freeserve.co.uk/england1.htm) says "This area lies predominantly in the county of Cumbria, but the orefield stretches into the edges of the neighbouring counties of Durham and Northumbria".
And on http://www.minfind.com/mineral-10097.html there is a stunning price asked for a piece not too different from yours!
Hello Episcophagus, I think that it is a galena. I hope it is as i've got a 7 kilo piece. I am going to Newcastle museum on friday to find out, I will get back in touch with you as soon as I find out.
Thank You for all your help with this,much appreciated.
I hope you don't think you have became rich - the price asked on that web-page is outrageous. Galena is just lead ore (lead is right now about $1/lb - but rising) however it often contains some silver (up to 1%) too... (see this discussion: http://www.mindat.org/mesg-6-105595.html).
Also note that lead is poisonous, and thus galena is poisonous too. It could be wise to wash your hands after handling it.
UPDATE It's not galena as galena melts at around 700 f. I heated a piece at 1700 f for 4 minutes and it didnt even glow red, I then hit it with a hammer and it didn't dent it. It also cuts glass. Any suggestions?
Galena (i.e. lead sulfide) melts at 1118 °C = 2044 °F according to Wikipedia. See http://en.wikipedia.org/wiki/Lead(II)_sulfide.
Other sources give 1114 and 1115 °C (for instance http://earth.geology.yale.edu/~ajs/1969/ajs_267A_11.pdf/233.pdf). But this might be caused by impuity? Ag2S melts at 825 °C.
Pure lead melts at 327.46 °C (621.43 °F) - but galena is something quite different than pure lead.
How to do to get lead out of the galena - see http://www.geo.fu-berlin.de/geol/fachrichtungen/geochemhydromin/mineralogie/pdf/quickassay.pdf (lead on p. 54 and reducing PbS with charcoal and NaCO3 p. 20-22).
Did you find out what it was???