Rob

I'm not aware of any quantified rarity values for individual brockages, but given that they are only produced when the manufacturing process goes wrong, it follows that they are all at least rare. They crop up randomly in auctions and so the price doesn't have a reference book value. Typically they are not in the highest grade although these are occasionally found. For young head pennies, there were 3 obverse brockages in the Adams auction at Spink in July 2003. Freeman 2 obv. toned VF sold for £80, Freeman 6 obv. gEF with a little lustre sold for £260 and Freeman 2 obv. UNC with nearly full lustre sold for £620. All prices exclusive of buyer's premium. The last coin was exceptional due to the quality of strike and extreme rarity in that grade. In typical circulated grade, a reasonable rule of thumb is double the list price or maybe a bit more than that for a normal piece. Alternatively, realistically grade the brockage and value it at the price for a normal piece but one grade higher. Realistically grade specifically excludes typical ebay grading.

Yes we should where the item is not as described to the detriment of it's value. Both for dross and for high value items if it is apparent someone is trying to pull a fast one. My own recent experience includes a Pontefract 1/- which was on ebay around Christmas time. It was high grade and worth about £3000-3500, but the seller didn't say it was plugged reducing this value considerably. I only found out when the prices realised list for the provenance given indicated that the item didn't sell at the auction. On a day when most things were 30% above estimate, this piece should have made £2K easily and so an unsold piece with an estimate of £1300 ie £700 below market value or so sets alarm bells ringing. Suffice to say a piece with the same errors in the same description (think copy and paste), but this time not pictured and with a note to the effect that it was expertly plugged appeared in the next auction where presumably the vendor acquired it. I informed the high bidder and it saved us both bidding to probably 2-3 times its value. The vendor was asked if it was plugged and he denied it, but confirmed my suspicions by sending a hi res scan. You don't casually acquire a Pontefract 1/- without doing your homework, it's just too much money to risk. A foreign seller could have been difficult to chase too. As an aside for the instigator of this thread, whom I presume is the same tomgoodheart. I am still a bit miffed over the AVSSPCE, but a good rare piece struck from different dies to Brooker 425. It looked as if it could have been from the same obverse die as 427 with the colon stops, though doubtless you will tell me.

What is the rarest coin you've seen mutilated? An enamelled 1698 OCTAVO halfcrown (R6)

£16000 hammer.

You and me both Chris. I thought the further up the periodic table you went the heavier the elements got, since lead is after gold i would have though it had been heavier. Unless it a bonding thing? Perhaps gold atoms are closer than lead ones meaning there's more in a certain area, which means that although they are lighter overall the difference balances out in gold's favour.* *That's a guess (not based on principles but just me making it up) So if i'm wrong... well i agree. Basically right. The density depends on the lattice structure of the solid which is determined amongst other things by the outer electron shell of the atoms concerned, together with an increasing density as you increase the atomic weight due to the presence of a heavier protected atomic nucleus nucleus. Based on these 2 main criteria, the relatively less dense elements in the list such as aluminium, tin, antimony and lead have s and p orbital electrons in the outer shell whereas the relatively denser ones such as copper, nickel, gold and silver have s and d orbital electrons in the outer shell. Hence you can get misconceived preconceptions of which is metal is or should be "heavier". Add platinum at 21090 kg/m3 to the previous list. It has a less complete outer shell than gold and so offers greater possibilities for bonding. More bonds = tighter lattice. Not a full explanation but hopefully clear enough.