Tianqi last December bought a 23.8 percent share in SQM from Canadian fertilizer company Nutrien for $4.1B, the largest deal in history for a lithium asset.
In April, ethical investors working on a global standard for tailings dams had written to 683 listed resource companies, including major miners, asking for information to be made public within 45 days about every facility they control.
The international group says sales of polished diamonds below 0.50 carats are slow due to excess supply, weak Chinese demand and tight Indian liquidity.