Platinum jewelry connoisseurs in London are turning their attention to an upcoming sale, where three beautiful platinum items will be auctioned.

Lot 283, an art deco diamond brooch from 1925, is perhaps the most unusual of the three and auctioneers expect it to sell for around $1,000.

Based around a collection of old brilliant and single-cut diamonds mounted in platinum, the rectangular brooch is 4.3 centimeters in length and it seems certain to attract a huge amount of interest.

A 2005 ring will also be sold at Bonhams on August 8th, with auctioneers predicting a sale price of approximately $1,200. The ring is centered on a square radiant-cut diamond within a four-claw platinum setting and it is hallmarked London from the year it was produced.

More impressive still is a diamond single-stone ring from 1976, which has import marks for London from this year. The ring is notable for the brilliant-cut diamond within a six-claw platinum setting and it is likely to sell for upwards of $4,000.

Later in the month, a Bonhams sale in Carmel, California, will see an even more spectacular platinum ring sold at auction.

The tanzanite, diamond and platinum ring has an estimate of $5,000, making it one of the most expensive items of the day.