Diamonds are not always a girl’s best friend. Blythe Lawrence lost the first diamond she ever handled, in a class at the Gemological Institute of America in London.

“They told us if we lost it we would have to pay for it,” the 19-year-old Bermudian said. “They didn’t say how much it was worth.

“You have to hold the diamonds in tiny tweezers and I was holding a diamond that was oddly shaped.

“I flung it across the room, by mistake. I was sweating until we found it again.

“Several times I lost stones in the microscope itself, which is not supposed to happen. Everyone in the class dropped them in the beginning.”

Despite the mishap, she soon learned to handle the gems and this week earned her diploma from the GIA.

Her graduation was particularly poignant because she had been a diamond in the rough when she was in high school.

“In my last year at the Dublin School in New Hampshire, my parents wanted me to choose a career path and I didn’t know what I wanted to do,” she said. “I have a short attention span.

“I liked rowing and art. I thought I would make myself crazy doing art as a career. I didn’t want to spend four years studying something I wasn’t committed to.”

Then her mother, Michele Lawrence, pointed out that she had had another passion since she was a child.

“I always liked shiny things and would pick them up randomly,” said Miss Lawrence. “I was the family magpie.

“My older sister, Freya, had a collection of costume jewellery from being in drama productions. I just took that over as mine. I didn’t do anything with it; it was just mine and I loved it.”

So when her mom suggested that she look into jewellery as a possible career, the idea seemed right. Then, on a family cruise, a jeweller suggested that she study at the GIA, because it is highly respected and sets the standard for diamond grading.

Despite the missing gem, Miss Lawrence knew from the first day that she was on the right path.

“I was just so excited to handle a diamond,” she said. “I just loved the course. It was an intense, hands-on, six-month course, split into two parts.

“The first two parts involved diamond grading and the rest was about identifying coloured stones.

“I liked identifying coloured stones much better than diamonds, because there are a lot of visual cues.

“I got really good at identifying stones visually. I can tell some stones are glass just by looking at them.”

She learned how to use various types of equipment to measure the weight of gems, light refraction and to reveal tiny visual cues. Quartz, for example, has a unique telltale bullseye under close examination.

Miss Lawrence was fascinated by a field trip to Sotheby’s of London.

“At the auction house we picked up a few rings and were asked to take a stab at grading and identifying them,” she said.

“We were all competing to see who could come closest to the answer. I would like to work at Sotheby’s, introducing people to different jewellery pieces.

“I think I would need to get an apprenticeship to do that.”

To graduate she had to take a multiple choice test, and correctly identify 20 different coloured stones and grade a similar number of diamonds.

A single wrongly identified stone meant failure.

“I got all 20 coloured stones right the first time,” Miss Lawrence said, proudly.

She said the programme changed her outlook in a number of ways. Now, she cannot go into a jewellery store without casting a cynical eye.

“I am very fussy now,” she said. “We go to a market in London that sells jewellery and I can’t help thinking that the stones people are selling can’t be worth that much, as they are selling so many of them at the same time.”

Her instructor warned her not to evaluate the jewellery of her family and friends.

“If you go around telling people their wedding ring isn’t really worth that much, you’re bound to lose friends,” she said.

Gemologists tend to work in laboratories or in the field identifying rough stones. But Miss Lawrence does not think that this is the route she will follow.

“The course has ignited an interest in jewellery design, and this is probably the direction I will take,” she said. “I would like to try metal smithing.”

• For more information about the GIA in London, see www.gialondon.co.uk.