Table of distribution of Rare Earth reserves and mine production (http://www.wikinvest.com/wiki/China%27s_Rare_Earth_Dominance). As you can see, China does not own all Rare Earth Oxide Reserves but does account for close to all mine production, it is safe to assume that the same goes for other forms of Rare Earth elements.
Country Reserves (t REO) 2006 Mine Production (t REO) 2007 Mine Production (t REO) 2009 Mine Production (t REO)
United States 13,000,000 0 0 0
Australia 5,400,000 0 0 0
Brazil 48,000 730 730 650
China 36,000,000 119,000 120,000 120,000
CIS 19,000,000 N/A N/A N/A
India 3,100,000 2,700 2,700 2,700
Malaysia 30,000 200 200 380
Other Countries 22,000,000 N/A N/A N/A
World Total (rounded) 99,000,000 123,000 124,000 124,000
Source: Mineral Commodities Summary 2010, U.S. Geological Survey (t REO = metric tonnes of rare earth oxide)
Additionally, this is quite interesting:
From the same site, http://www.wikinvest.com/wiki/China%27s_Rare_Earth_Dominance
How is China dominating rare earth supply?
Of late, China has taken a number of steps to cement its monopoly of the global rare earth market. First, in each of the last 3 years, the country has reduced the amount of local rare earth production that can be exported.[4] The total export quota for 2010 is 30,258 tonnes, 40% less than the 50,145 tonnes for 2009.[11] Second, China appears to be forcing manufacturers that use rare earths to move onshore by using export quotas to limit the availability of these materials outside the country.[6]
>>>>> Last, but not least, the country has made moves to buy other rare earth resources around the world. When credit markets collapsed in 2008, government-owned mining companies stepped in to acquire 52% of Lynas Corporation and 25% of Arafura Resources, which plan to open mines in the next few years that would have a combined production equal to 25% of the global rare earth output.[6] <<<<<
As, according to the Newspaper article I read, China's rare earth element mines are supposed to run out in 20 years if they continue mining at this rate, these steps are crucial. Not only do they drive the price of the elements up and allow China to use it as a means to influence politics with, it also prolongs the period over which China can continue mining these elements (obviously).