How ? What would be heavy enough ? Of course Tungsten weighs like Gold, but does anything weigh like platinum ?
You could make a silver amalgamation and coat it with platinum, I suppose. Maybe throw some Ti into the mix to get the amalgam to be harder. Core = Ag/Hg amalgam Outer-core = Ti Outer-shell = Pt Edit: Maybe use Fe instead of Ti for an outer-core, then Ti- as an inner-shell. I forgot that Ti might dissolve into the leaking mercury.
Osmium and Iridium are heavier than Platinum. But both are not easy to work with and have high melting points. NK, not quite understand what you are implying? A silver amalgam will fail the density test.
Both metals are expensive but I believe both their spot prices are lower than Platinum and these days anything is possible couple years ago no one would have believed in tungsten bars.
Spot price if iridium is ~$1050, platinum is ~$1650. You might make a few bucks but it hardly seems worth it when you consider the costs of making the fake.
Most people don't have the equipment to readily determine if it is a tungsten fake or not, not even a SP.GR. device, so the key will be how good they copy the markings, and that is a lot easier.
I have seen some fake Credit Swiss platinum bars floating around lately. I'm not sure what they are made of but I have seen them. They are in a card like the real bars.
Again, acquisition costs on the Iridium would be higher. If the markets see someone acquiring Iridium in bulk (which would be necessary to make enough volume for this to be profitable), the spread would shrink VERY rapidly. In terms of cost viability, I'm pretty certain Fe encased Hg (or HgAg) with a Pt plate is the best bet.
Was just digging through Ebay and was wondering how this guy is getting away with selling these "fun gifts" which don't appear to have any markings on them listing them as fake... http://www.ebay.com/itm/NEW-1-1-oz-Clad-999-5-PLATINUM-CREDIT-SUISSE-BAR-100-Mill-Great-Fun-Gift-/110983201142?pt=LH_DefaultDomain_0&hash=item19d71d4176 EDIT: Ok nevermind, they do say copy on the back, but dang!