[Coign]

But the fact is if you look long enough, you will find identical "looking" snow flakes.

Wilson A. Bentley, a farmer who was born, lived and died in the small town of Jericho in Vermont was called “The Snowflake Man”. He supported this “all snowflakes are different” theory. Around 1884, at the age of 19, he became the first person to photograph a single ice crystal, by cleverly marrying a microscope to a camera, using an adjustable bellows mechanism. In 1920, the American Meteorological Society elected him to the state of Fellow. They also awarded him their very first research grant, in recognition of his “40 years of extremely patient work” - for which they gave him $25. He continued working in this field until his death in 1931, by which time he had taken 5,381 “photomicrographs” of individual snowflakes. Towards the end of his life, he said that he had “never seen two snowflakes alike”. And so the story arose that all snowflakes are different.

But in 1988, the scientist Nancy Knight (at the National Center for Atmospheric Research in Boulder, Colorado) was studying wispy high altitude cirrus clouds. Her research plane was collecting snowflakes on a chilled glass slide that was coated with a sticky oil. She found two identical (under a microscope, at least) snowflakes in a Wisconsin snowstorm.

They were hollow hexagonal prisms, rather than the classical six-spoked star-shapes – but as far as snowologists are concerned, they counted as snowflakes. But if you want to be pedantic, they probably weren't identical if you were to look at the actual molecules – but at this level, is anything identical?

Since the earth was formed about 4.5 billion years ago, about a million million million million million snowflakes have fallen – but Mr. Bentley made his pronouncement of the cold hard facts after looking at just over 5,000 of them.

http://www.abc.net.au/science/k2/moments/s1784760.htm