Sharapova in, Cilic out of US Open

Russia superstar Maria Sharapova was hardly tested before rolling into last 16 with a convincing win against American teenager Sofia Kenin while former champion Marin Cilic of Croatia was knocked out from the US Open on Friday.

Sharapova, in her first Grand Slam tournament after serving a 15-month doping ban, advanced into the fourth round bt defeating 139th-ranked Kenin 7-5, 6-2.

The five-time Grand Slam champion and former world number one, now ranked 146th, will try to claim a place in the quarterfinals on Sunday against Latvian 16th seed Anastasija Sevastova.

Earlier in the day, fifth seed and 2014 champion Cilic was defeated in the third round, losing at 4-6, 7-5, 7-5, 6-4 to Argentina's Diego Schwartzman.

"My injury played a quite significant part in the loss, and just being injured and not being able to keep the good form," Cilic said after the match.

Elsewhere, double Wimbledon winner Petra Kvitova of the Czech Republic advanced with a crushing 6-0, 6-4 defeat of France's Caroline Garcia while Venus Williams of the United States got past Maria Sakkari from Greece 6-3, 6-4 to make last 16. Third seed and Wimbledon champion Garbiee Muguruza of Spain swept past Magdalena Rybarikova from Slovakia 6-1, 6-1 to also reach last 16.

However, Kosior said the amber jewellery of well-known designers and good quality amber, gold and diamond products continue to be "very well" sold.

"We can observe the discrepancies of prices -- yellow, milk amber types, those of a major interest of Chinese buyers are of much higher price than the transparent type. So are the unique, individual stones. The prices however are lower than a year ago," Kosior said. According to Kosior's forecast, the prices are going to stabilize and then will rather go up than down.