A host of US jewellers have commented on the buying habits of American couples when they get engaged, with platinum proving a popular choice for those in their 20s.

White gold is said to be very popular at present, with Goodman Jewelers manager Brad Haack identifying a new trend.

"Right now, the white gold is very in," he commented.

However, different age groups appear to prefer different metals, with couples in their 20s fans of lighter metals such as 14 carat white gold or platinum.

"Couples 50 years and up (get) yellow gold, and then the 30s and 40s are kind of a mixed bag, and they favour white or yellow (gold)," Hans Soukup, a buyer for Lasker Jewelers, explained.

The most popular time for men to pop the question now appears to be spring, with summer weddings particularly popular and nowadays couples tend to visit jewellers to pick out their rings together, according to the Spectator.

Last week Platinum Guild International USA initiated a new promotional campaign entitled The Platinum Privileges Program in a bid to exploit the growth in popularity of platinum bridal jewellery.

The scheme involves a "platinum value umbrella" and will be run in conjunction with a number of wedding-based publications, including Modern Bride, Bride's, and Elegant Bride Magazine.

Offering a series of discounts and reductions, the initiative also offers the chance to win a piece of platinum bridal jewellery from Ritani worth more than $3,600.