Snowflakes — those intricate, one-of-a-kind ice crystals — form when precipitation falls through varying levels of humidity and temperatures in the air. While plenty has been written about the science of snow, we're focusing on the sheer beauty of them. Here are 18 to study and admire.

A close-up of a snowflake against a black background A crystalline snowflake against a smokey and black background. (Photo: Andreas./flickr)

Various flat snowflakes against glass Various flat, but still beautiful, snowflakes against glass (Photo: N!(K/flickr)

Crystalline snowflakes against a purple background Crystalline snowflakes against a purple background. (Photo: Eric Bégin/flickr)

A snowflake rests on a branch with acorn Snowflakes can land just about anywhere, including tree branches. (Photo: Nedra/flickr)

Snowflake lands in a person's hair Speaking of landing anywhere, snowflakes in a person's hair (Photo: Gui Seiz/flickr)

Various snowflakes on a blue background Dentrite snowflake crystals show up against the surface of a pick-up truck. (Photo: Julian Colton/flickr)

Snowflakes photographed along the curve of an airplane's window. Snowflakes photographed along the curve of an airplane's window. (Photo: ~ezs/flickr)

A single snowflake rests in frozen pines or asphalt The dark background here really makes the intricacies of the snowflake stand out. (Photo: mommamia/flickr)

Snowflakes on glass with frost Snowflakes and frost on glass make for a wintry scene. (Photo: JimmyMac210/flickr)

Snow that looks like rice or grass Snowflakes can even look like rice. (Photo: netzanette/flickr)

A perfect, whole snowflake rests on a plank. A perfect, whole snowflake rests on a plank of wood. (Photo: Julie Falk/flickr)

A snowflake lands on a woman's eyelashes You're supposed to catch snowflakes with your tongue, not your eyelashes. (Photo: Roswitha Siedelberg/flickr)

Snowflakes on glass When snowflakes are about, why focus on anything else? (Photo: Thomas Marthinsen/flickr)

Snowflake pile-up Even piled on top of one another, individual snowflakes still find a way to stand out from the crowd. (Photo: Julie Falk/flickr

A formation of ice crystals Snowflakes and their intricate ice crystals make each one unique. (Photo: Jason Ahrns/flickr)

Rice-like snow lands on a leaf Snow doesn't always end up on the ground as we've seen, and sometimes it'll end up on winter leaf. (Photo: Margot Trudell/flickr)

Snowflakes on a dark background Until next winter, one last snowflake. (Photo:Rachel/flickr)

Catie Leary ( @catieleary ) writes about science, travel, animals and the arts.