The 50-year-old is one of growing number of Hong Kong people who are choosing a less traditional way of remembering their loved ones.

Tang had part of the cremated ashes of Kennedy made into a synthetic rough diamond, which she wears constantly with a cross on a chain around her neck.

'Wearing his diamond means I feel his presence every day. It is like he is with me, helping me to continue to run our business,' said Tang.

'When I feel frustrated and helpless I also talk to my diamond. It also means I can help fulfil a wish of his to travel to places he wanted to go, but never had the opportunity.'

Scott Fong Sze-kok, director of Algordanza Hong Kong, offers the diamond transformation at a cost of HK$25,000 to HK$290,000.

He says business has increased by around 50 per cent every year since the company was launched in Hong Kong in 2009. 'We found Hong Kong people to be quite open to the idea of remembering someone this way,' said Fong.

'It is particularly appropriate for people who had a strong bond with the deceased, such as husbands and wives, or parents and children.

'I think it is the idea of being able to keep someone close which is the main reason people choose a remembrance diamond.'

The process of converting cremated remains into a diamond takes around six months.

It involves extracting the carbon from the ashes and then subjecting it to high pressure and high temperatures in Algordanza's Swiss laboratory, recreating the conditions which form natural diamonds.

Fong said clients are able to choose the size and jewellery design for the diamond, with costs ranging from HK$25,000 for a raw 0.25 carat diamond to HK$290,000 for a 2.0 carat cut diamond.

What they can't choose, said Fong, is the colour, which usually has a blue hue because of the natural elements within the ashes.

The cost of the diamonds is far higher than storing ashes in government niche, which costs between HK$2,400 and HK$4,000. But is similar to the cost of private niches, which cost from HK$50,000 to HK$350,000.

Tang heard about the memorial diamond service from a newspaper article and said she discussed it with her husband while he was still alive.

She said she chose to keep the diamond in its rough format, rather than cut, because she felt it was perfect as it was - just like her husband.

But as the couple have no children to pass the diamond on to, she has also reserved niches for them both.

'I am very proud of my diamond. When my time comes I intend to have my remains made into a diamond, which I will have put with my husband's remaining ashes.

'His diamond, I will have put with my ashes,' she said. 'That way we will always be together.'