April - the traditional birthstone is Diamond.
The following information is taken from Thaigem.com.
The hardest, rarest, densest natural substance known to man, diamonds have been a source of fascination (and misinformation) since 800 BC when they were first presented to royalty in India. In those days the Indians believed that diamonds were created when lightning struck rock. Amazinely the sub-continent was the only producer of diamonds for an astounding 2,500 years.
As bewitching as diamonds are they have produced more than their fair share of myths over the centuries.They've been attributed with increasing potency, preventing lechery, driving away nightmares, counteracting poison, warding off evil, protection from wild beasts, healing sickness and (naturally) attracting good fortune.
There's also the lie detector myth: that diamonds will darken in the presence of a guilty person and brighten in the company of an innocent one; and the magical reproduction legend: that diamonds sprinkled with morning dew and left in the dark can reproduce offspring! If only!
Despite these fanciful ideas some of the amazingly real attributes of diamonds include: their age - the first diamond deposits were brought to the surface of the earth approximately 2.5 billion years ago while the most recent deposits are roughly 50 million years old; their hardness - diamonds are so hard they can only be polished by other diamonds; rarity - more than 250 tons of ore need to be blasted, crushed and processed to yield one carat of rough diamond and of that rough, only 20% is suitable for gem cutting; density - diamond is so dense that it actually slows down light to less than half its normal speed - 80,000 miles per second; fluorescence - if you're in a nightclub and someone's ears or fingers start to glow then diamonds are most likely the culprit, 30-40% of diamonds glow blue when exposed to ultraviolet light and some will even glow green, yellow, white or (extremely rare) red.
While Africa is known as the Diamond continent, it is actually in Australia that the largest reserves are to be found - including the very rare and highly valued pink and red fancy colored diamonds.
Diamonds weren't cut until the 14th century and it wasn't until 1725 that deposits were discovered in Brazil and it wasn't until 1866 that l South Africa's substantial storehouse was unearthed.
Diamonds are made of pure carbon atoms that exist deep in the ground, and these are then exposed to intense heat and pressure over billions of years. Over time, this pressure builds up and forces the diamonds and rocks up toward the surface in a volcanic-like explosion. The explosion creates a very deep, wide hole called a "kimberlite pipe" into which most of the diamonds settle. These "pipes" resemble gigantic carrots encrusted with diamonds. It can take years to fully excavate an entire pipe.