RAPAPORT... The UK has imposed heavy tariffs on Russian diamonds as it attempts to up the pressure on President Vladimir Putin following the country's invasion of Ukraine.The government has increased import duties by 35 percentage points on a range of precious and semiprecious stones and metals from Russia and Belarus, it announced last week. These include rough and polished diamonds - whether natural or lab-grown - as well as pearls, colored gemstones, precious metals and jewelry.Tariffs on diamond imports were previously 0%, according to the UK government website. This means they will now be 35%.The measures build on earlier UK sanctions against Russia, including a ban on doing business with Alrosa, the country's main diamond miner. In last week's update, the government also prohibited the import of silver from Russia."The UK continues to stand shoulder to shoulder with Ukraine and is working closely with our international partners to inflict maximum damage to Putin's regime, reducing the resources and funds he needs to carry out this illegal war," said international trade secretary Anne-Marie Trevelyan.