I was shocked to learn this week that consumers in Brighton looking to purchase jewellery for a special occasion - an engagement, wedding or important birthday - are being let down when it comes to ethical purchasing choices.

Research carried out by the Green Party found that the majority of the city's jewellery retailers were unable to guarantee - or prove - that their gold or diamonds are from ethical sources.

According to pressure groups such as Cafod ( http://www.cafod.org.uk/key-issues/mining ) mining for gold has been linked to a host of serious human rights and environmental abuses in countries such as Honduras and the Democratic Republic of Congo.

Diamonds have been blamed for fuelling and perpetuating armed conflicts across Africa - thus the term "blood diamond" , itself the title of the now-world famous feature film.

Our intrepid ethical shopper visited 21 of the town's leading jewellery shops and workshops - ranging from big chain stores to small independent outfits - and quizzed them on the origins and ethical status of their goods.

None, with the exception of one or two who carry specifically ethical ranges, were able to say with any certainty where their gold comes from, or prove if it was ethically procured.

One larger store stated it was part of a scheme designed to avoid the use of gold from dubious origins.

On diamonds, all the stores we spoke to claimed that they only sold "conflict free" stones. Yet only one could provide the relevant Kimberley certificate proving this. (The Kimberley Process is an international mechanism for controlling the trade in conflict diamonds)

The others only had their suppliers word (often a few lines of small print at the bottom of an invoice) to reassure customers or broad statements saying all their products are "responsibly sourced".

Example documents shown to our ethical shopper were less than reassuring, one invoice reading "as far as we are aware... all our stones are ethically produced". Several claimed to be signed up to the Kimberley Process but could offer little to back this up.

There's no suggestion that all of the gold and diamonds being sold by these Brighton retailers are from unethical or questionable origins.

What's worrying though, from the consumers point of view, is that very few retailers were able to offer reassurance or guarantees. Guarantees are what the disconcerning consumer needs in order to make informed choices.

Not all the blame can be placed at the feet of retailers however. Some genuinely don't know where their gold or stones come from, and - bizarre as it may seem - are unaware of the problems associated with its production.

One of the problems with gold is that - at present - there is no single, universally approved or recognised ethical certification process in place. But the claims of several retailers that it is "impossible" to know 100% where gold originates from are frankly incorrect.

There are some excellent ranges of ethically sourced gold available, including those produced by the local, Sussex based Cred Jewellery ( http://www.credjewellery.com/ ) .

The company, run by campaigner and entrepreneur Greg Valerio, says it is entirely possible to put in place a gold supply chain that is fully transparant and open to ethical audit. As he was due to point out at an event with Brighton's Our Ethical Network ( http://www.ourethicalnetwork.com/ ) earlier this week, if they can do it, why not others?

Here in Brighton, a host of similarly pioneering retailers and producers lead the way in ethical procurement, be it for food, clothing, toys or garden furniture. They deserve our continued support.

But we consumers should also encourage other retailers to stock ethical ranges, and sign up to certification schemes such as those administered by the Fair Trade Foundation, the Soil Association and the Kimberley Process.

Why not work with Brighton's craft sector to make its famous jewellery quarter Britain's first centre for ethical jewellery? It would be good for business and better for people and the planet.