alt Hacker NewsReserves means something specific in the context of minerals! Reserves measure 'economically viable' deposits. [1]
There used to be tons of tungsten mines in the USA, e.g. in Colorado linked below.
[1] https://resourcecapitalfunds.com/insights/rcf-partners-blog/...
[2] https://coloradogeologicalsurvey.org/publications/tungsten-m...
Yes, but it should be emphasized how dependent "Reserves" are on both exploration work, and current assumptions about future mining/refining/market conditions.
China's secret to having most of the world's Reserves may be that they bored a lot more test holes (to actually know "the rock in >THIS< spot is X% tungsten") than anyone else, then made some more-optimistic assumptions.