Marilyn Monroe may have said that diamonds are a girl's best friend in the '50s - she was just sharing a girlie secret. Hollywood's most-glamourous ladies do not leave home without their solitaires. From Demi Moore to Sharon Stone, you will always notice, no matter what designer dress they wear - their ears are always sparkling with the glitter of diamonds. Last year's Oscars had every one sporting a simple solitaire around their necks. A new trend was not born, an old one just lingered on and on. It also proved that what is classic remains in style.This single stone also seems to be gaining popularity in India as well, especially with the younger generation. From on-screen stars to off-screen celebs these expensive rocks are the preferred choice. Chosen over the heavy gold sets their mothers wore. Says Ramona Garware, "A solitaire looks more classy than anything else." The wife of industrialist Jaideep Garware, this twenty something prefers her diamond studs to a big flashy piece of kundan. As doesAvanti Birla. Daughter-in-law of the Birla family, Avanti has always set fashion trends in the city and now she is entering the world of fashion. Her opinion counts, so when she says, "A solitaire does not look flashy or like you are trying to make a statement," you know that the rest will follow. Avanti may wear larger, chunkier gold jewellery for weddings and formal soirees, during the day she remains faithful to her single stone.Neelam, film actress and television anchor, is cut from the same mould. She comes from a family that has been in the jewellery business for XY years, and she sticks to her solitaire earrings in spite of a huge choice. "They go with both a casual and formal look," says Neelam.This versatility also translates into the field of finance. Buying a diamond has become good business sense. "Now, diamonds are seen as a better investment," says Inter-Gold's Priti Mehta. If you are buying a diamond purely as an investment then celebrity designer Farah Khan advises that you pick upmedium-quality diamonds. "These are the easiest to sell again. Finding a buyer for a top-quality diamond can be very difficult," she says. While gold prices have dropped, the diamond just seems to be becoming more and more valuable. But unlike gold, a plain-set solitaire comes without making charges. "You do not waste any money in setting a solitaire," says Farah. Luckily, this setting sans frills is also the most preferred. "The young elite basically prefers a single-set diamond," adds Farah. And she practises what she preaches. Like Priti, she prefers to wear solitaire ear rings - "They are elegant, easy to handle and do not pull you ears," says this jewellery designer. "They match everything and you can wear them to work without looking overdressed. They look fine in the evenings too," says Priti.There is still one factor that deters an average client from buying a solitaire - the price. But it's not as daunting as you think. A small solitaire (or half-a-carat diamond) would set you back by Rs 65,000.That is about the same price as an Abu-Sandeep sari. A steep price if you consider that a diamond is actually a piece of a carbon - the same substance that used to power steam engines. Well, almost. Carbon crystalises 150 miles below the earth's surface and under immense heat and pressure it becomes a diamond.Like its enduring appeal, a diamond is the hardest substance known to man. To get a carat of diamond polished, men have to blast, dig and crush 250 tons of earth. And of all the rough diamonds found, only half of them are suitable to be put through the cutting process.Then these perfectly polished stones find their way to celebrity ear lobes. "Most people buy solitaires in pairs for ear rings. And if they buy just one it is normally for a ring. A single stone for the neck is the last priority," says Farah. That is changing. Under 30's are sporting diamond necklaces more and more, a fact Farah encourages. People are also getting more adventurous with the shape of stone they sport. "A round diamondhas 58 facets so it sparkles more than other shapes as more light reflects off it. But the young are opting for heart-shaped diamonds and the marquis is not as popular as it used to be," says Farah.Whatever the shape might be, a diamond symbolises eternal love. A solitaire ring is the most common symbol of an engagement - a prelude to the mangalsutra like . This custom began in 1477 in Austria when Archduke Maximillian gifted his fiancee a diamond ring 24 hours before they were married. A custom that has endured like the diamond.