What the depth? This snowflake has a seemingly impossible number of layers to it! How can such a small crystal be so complex? My guess is either a strange form of crystal twinning, or dumb luck.
A simple hexagonal plate snowflake can usually have detail in three places: the front, the back, and inside. Interesting fact: if there are surface details on one part of a snowflake, the other side is smooth aside from rings or curved lines caused by inward crystal growth. Much of what we are seeing here are bubbles trapped in the ice, with a few more saturated ones near the center that are so close to the surface they evoke the phenomenon as thin film interference – the same physics that puts rainbow colours in soap bubbles).
The mystery here is that there appears to be multiple distinct layers of bubbles, something very rare. It would require two snowflakes to be stuck on top of each-other, or it could be two twinned crystals. These usually take the form of column-type snowflakes with an “evaporation groove” showing their separation (example: https://www.flickr.com/photos/donkom/16376573941/ ). I’ve seen it happen once before (long ago: https://www.flickr.com/photos/donkom/8476502160/ not just a plate twin, but TWO of them!) in plate-type crystals. This would allow for multiple layers, but in the earlier example I link to, each crystal twin as the same footprint! This is true for nearly every twin I’ve encountered, but it’s not true here.
Notice the brighter inner area? It forms roughly into a smaller hexagon which is the would-be twin, brighter here because there are more layers of ice to reflect light back. How can one outgrow the other when their footprints are glue together? The only suggestion I have is crystal splitting – where a bubble forms around the entire circumference of the snowflake, effectively cutting one of the crystals in half. With signs that the bubbles forming in the ice are very near the surface (which can create colours), if a thin top plate formed, it usually accelerates its growth beyond its partners (knife edge instability).
In this scenario and only this scenario could this happen: splitting twinned crystals. Or, just dumb luck that two snowflakes fell onto each-other perfectly. Such luck isn’t that uncommon – it’s what leads to the creation of twelve-sided snowflakes when two smaller crystals collide and stick together at a perfect 30-degree offset in rotation. Sure, they don’t show themselves very often, but I see a handful a season.
This snowflake measures just over 1 millimeter across, and originally it didn’t get my editing attention because it felt too cluttered – and then I realized that there was a puzzle to put together based on the abundance of details.
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