(IDEX Online) - Researchers believe diamonds found in Canada are 2.7 billion years old - and say they provide compelling evidence that the Earth is considerably older.They say the tiny gems are effectively acting as time capsules. Minute quantities of gas trapped inside them reflect the chemical composition of the Earth's mantle at the time they were formed.What they reveal is that the proportions of chemicals vital to life - such as hydrogen and nitrogen - were largely the same then as they are now.Most samples other than diamonds have been destroyed in the intervening years," said Michael Broadley, lead researcher from the University of Lorraine, France."Diamonds however, are comparatively indestructible, they're ideal time capsules," he told the virtually-held Goldschmidt Geochemistry conference, based in Switzerland.His team used diamonds recovered at Wawa, near Lake Superior, for their research."These diamonds are incredibly rare, and are not like the beautiful gems we think of when we think of diamonds," he said."We heated them to over 2000C to transform them into graphite, which then released tiny quantities of gas for measurement". Pic courtesy Michael Broadley