ghost apple
© Andrew Sistema
Apple-shaped ice casing created in an orchard following an ice storm are pictured in Michigan
The 'once in a generation' freeze hit that the Midwest of the country earlier this year saw frozen lakes, record breaking temperatures and large-scale travel disruption.

But a Michigan farmer also captured one of the weather's more beautiful phenomenons - the 'ghost apple'.

Andrew Sistema said that while pruning his apples trees on his Kent County farm, he noticed a perfect shell of ice coating the fruit.

A peculiar and rare product of the recent influx of cold weather from the polar vortex, ghost apples form when rain freezes perfectly around the skin of the fruit.

ghost apples
© Andrew Sistema
Ghost apples are so rare because they require very specific weather conditions - where it is cold enough for water to freeze but also to allow the apples inside the casing to rot
Sistema said that the ghost apple phenomenon is so rare because it requires very specific weather conditions; it must be cold enough to stop the ice melting, but warm enough to rot the apples and turn them into mush.

This is only possible because apples have a lower freezing point than water, due to their higher sugar and acid content.

The result is a glassy, fragile apple-shaped orb that, while less tasty than the real thing - is certainly more beautiful.