DON'T be surprised if you're walking down the street and Shona Bain stops and asks to have a look at a necklace or a ring you're wearing.

One half of Scottish jewellery brand Sheenashona - set up with her sister Sheena three years ago - Shona says she is always on the lookout for new ideas.

"The other day I was at the airport and asked to see a girl's ring and took a picture of it," she laughs. "It was made of chain and I thought, 'That's a little bit different, what can we do with that'?"

Ayrshire sisters Sheena and Shona, in their 40s, both had successful careers in design and oil and gas respectively before branching out on their own.

"I thought, if you're going to do a brand in Scotland it's got to be a luxury brand. I love jewellery so I said, 'Let's have a jewellery company'," says Shona.

They spent time researching the market and scoured the country to find the best UK manufacturers before launching their website www.sheenashonajewellery.com and selling their first collection online in 2012. Now two years on the range of necklaces, rings, bracelets and earrings, as well as pieces for men, can be bought at House of Fraser, Glasgow's Blythswood Square hotel and the city's Corinthian Club.

All the jewellery is designed and made in Britain and the distinctive purple and white packaging, inspired by a Fortnum & Mason chocolate box, is produced in Scotland.

"Sheena being the designer comes up with a lot of ideas," says Shona. "But we might be walking down the street and we'll see something, or we'll stop someone and ask to have a look at their piece of jewellery.

"We'll sit down and play with some ideas and then cast a model, then get samples we give people to try on and ask them what they think of it?"

Heart lariat necklaces and lockets are particular bestsellers. An engraving service means many of the pieces are popular for bridesmaid and best man gifts at weddings.

Shona explains that a lot of the new autumn-winter collection has been designed with the House of Fraser customer in mind, incorporating lots of gemstones - blue topaz, moonstone, green and purple amethyst.

A thoughtful touch in the design of many of the necklaces is the adjustable chain which means your favourite pendent can be worn with any style of neckline.

"A lot of our pieces adjust at the back. We notice when we watch women trying things on, we're all different shapes and sizes and sometimes the way it sits on you if you are slimmer or you are larger can vary," says Shona.

"Everybody wants to have it differently if you have a crew neck or a v-neck. More and more we are making everything adjustable so that someone can put it on and say, 'Tonight I'm wearing a higher neck dress but I still want to wear my favourite piece of jewellery.'"

Big sellers in the lead up to Christmas are a delicate silver ball and chain necklace in sterling silver and gold and silver lariat necklaces in which the gemstones can be swapped around.

"The jewellery market is moving towards fine jewellery. In the past there was lots of chunky silver and now everyone is looking at fine chains or necklaces in rose gold or yellow gold," says Shona.

"We have a great little bracelet that's basically rose gold with amethyst. You can wear one, you can wear three, wear as many as you want."

l www.sheenashonajewellery.com