New Delhi, Aug. 28 -- US president Donald Trump's decision to double tariffs on imports from India threatens to take the sheen off the country's diamond polishing industry, concentrated in prime minister Narendra Modi's home state of Gujarat.

India's natural diamond polishing industry is staring at its worst year in nearly two decades, with revenues projected to fall nearly 22% to about $12.5 billion in FY26, from $16 billion last year, according to a Crisil Ratings report released on Thursday.

The projected decline comes after Trump imposed a punitive 25% duty on the country for buying Russian oil, in addition to a same tariff levied earlier on Indian goods entering the US. The tariffs took effect on Wednesday. The steep 50% tariff on ...