UK shares join global rally, Rio Tinto surges on upbeat results

(Reuters) - Britain's stock markets jumped on Friday as investors cheered plans for gradual restarting of the U.S. economy and encouraging data on possible treatment for the COVID-19 disease.The commodity-heavy FTSE 100 index rose 2.7% by 0709 GMT, led by world's top iron ore miner Rio Tinto Ltd , which jumped 4.5%, after posting higher-than-expected quarterly production.The wider mining index gained 4.1%, with peers Anglo American and Glencore adding more than 4.5%.The domestically focused..