While we leaned heavily on the two lists our criteria were slightly different when it came to putting billionaires in the mining bracket.
Eike Batista, number one on MINING.com's list, does not appear in the Forbes mining and metals column for instance, despite his companies' extensive iron ore holdings and his roots in gold mining.
On the other hand we excluded many steel industry billionaires – who make up a substantial portion of the billionaires on the Forbes list – from our ranking.
If a steelmaker is vertically integrated (like most of the Russian firms are) and also has interest in mining iron ore, coal or other steelmaking resources he or she makes it in, but straight-up steel pipe makers, aluminium foundries and metal processors were excluded from our list.
Billionaires like the Reuben brothers whose fortunes were made in metal trading were excluded, but our list features fund managers and investors like Eric Sprott (#80) purely because he holds huge sway over precious metals markets and by his own admission holds 90% of his own assets in gold and silver.
Forbes includes only Anatoly Lomakin (#75) among mining-related billionaires while MINING.com counted five potash potentates – Dmitry Rybolovlev (#17), Alexander Nesis (#35), Anatoly Skurov (#54), Zelimkhan Mutsoev (#65), Filaret Galchev – and Andrei Guriev (#32) who made money in mineral fertilizers.
Inclusion criteria aside, 2011/2012 proved a good year for mining and metals tycoons, many of whom have clawed back losses suffered during the financial crisis or became freshly minted billionaires.
While the Uralkali and Silvinit potash merger made Russia's fertilizer kings even richer, Glencore's IPO last year added billions to CEO Ivan Glasenberg's (#20) fortune and created five others billionaires overnight. Apart from management Daniel Mate and Aristotelis Mistakidis (joint 40th on our list), Tor Peterson (#46) and Alex Beard (#51) we included private equity player William Macaulay (#78) for good measure. Glencore also helped Bulat Utemuratov (#64) return to the billionaire list after he sold zinc and gold mines to the Swiss resource company.
Others were not so lucky. Laksmi Mittal (#3) who after losing $10 billion over the past year is down to his last $17.5 billion and a number of Russians, including Mikhail Prokhorov (#12) and Vladimir Lisin (#8), had their fingers burned badly.
Another sign that mining can bring mega-riches is that notable figures in the industry such as Robert Friedland only manages position #50 despite having $2.3 billion in the bank; controversial diamond miner Lev Leviev sits at #57 with $1.7 billion in the bank and emerging platinum star Patrice Motsepe's $2.7 billion fortune doesn't crack the top 40 in mining.
Similarly, American coal dynasties are among the lower ranks with Christopher Cline at #61, Joseph Craft III (#65) and Jim Justice (#71).
Businessmen from Russia and the former Soviet republics still dominate the list although coal and iron ore in Australia and India, coal in Indonesia and silver and copper in Latin America are proving just as profitable.
MINING.com has put together profiles of the 40 top mining billionaires.