The development of the heart cut came at the end of the 19th century, by Wade of Boston in the USA, paved the way for the creation of the brilliant heart shape sometime between 1909 and 1910.
A cutter presented with diamond rough of low or pique clarity could choose to cut a heart shape if the appearance of inclusions could be minimised by having them in the décolleté, thus increasing the value of the yielded cut material.
Most heart-shape diamonds feature 56 facets (not including a culet). Of these, 33 are located on the crown and 22 on the pavilion - one and two fewer facets than a round-brilliant respectively. As with other fancy cuts, the stone may feature more or less facets depending on the rough.
The proportion is perhaps one of the most important factors to consider when judging a heart-shaped diamond; if the width is too great, the stone will look more like a butterfly than a heart. Likewise, if the length is too great, the stone can look like an arrowhead. Proportionately, the length of the stone - from the bottom of the heart to each side of the top - should be equal to the width with the décolleté running well into the outline.
Heart shape diamonds should have table and depth percentages similar to those of a round brilliant, but buyers will typically find a much broader range. A well-proportioned heart will return about 80 per cent of the optimum brilliance compared to that of a round-brilliant cut, so the concept of an ideal cut does not apply as it may with other cuts.
Large girdle facets in the décolleté area result in an obvious fish-eye effect and considerable light leakage with reduced brilliance.
Some of the most famous diamonds in the world are heart shape and two notable examples are a rare, natural blue colour: dating from 1909 to 1910, the Eugenie diamond is a deep blue and weighs 30.82 carats; The Heart of Eternity is a fancy vivid blue, weighs 27.64 carats, and formed part of the January 2000 sale of De Beers' Millennium Jewels Collection, which featured ten other blue diamonds totalling a massive 118 carats.
The heart-shaped diamond has enjoyed increased popularity in the last decade, following the release of the film Titanic, which featured a necklace set with a large, blue diamond aptly called the Heart of the Ocean.
This diamond was a movie prop based loosely on the story of the very real and famous Hope diamond. While the Hope was cushion-cut, it shares an owner with its cinematic sister in jewellery lover Louis XIV.
As art imitates life, so life imitates art. Following the release of Titanic, Harry Winston created a $US20 million blue diamond replica, while London jeweller Asprey and Garrard created a replica using a 170-carat, heart-shaped blue sapphire.
It's perhaps not surprising that Hollywood royalty and noted diamond collector Elizabeth Taylor has a magnificent, heart-shaped, yellow diamond, which was a gift from generous former husband Richard Burton.
This diamond dates back to 1621 when it was presented as a gift from Shah Jahan to his favourite wife, Mumtaz Mahal - if it wasn't enough to receive this hefty gem, Mahal will also be remembered for being the inspiration behind perhaps the best known symbol of love in architecture: the Taj Mahal.
The beauty, individuality and Hollywood's romantic connotations associated with the heart shape make it a very popular gift on Valentine's Day, as well as for significant anniversaries.