SafekipediaA snowflake is a single ice crystal that falls through the Earth's atmosphere as snow. Snow looks white because it is made from clear ice. The many small crystal facets of snowflakes scatter the sunlight, making it appear white to our eyes.
Each snowflake starts around a tiny particle called its nucleus. Water droplets freeze onto it and form a crystal. The shape of a snowflake changes as it moves through different temperatures and humidity levels in the sky. Sometimes, snowflakes join together, creating unique patterns.
Because of these changing conditions, no two snowflakes are exactly alike. They come in many different shapes and sizes. Scientists have found that snowflakes can be grouped into eight broad classifications with many types. The basic shapes include needle, column, plate, and rime, which can combine in many ways.
Formation
See also: Snow science
Snowflakes start from tiny particles in cold, wet air. These particles can be dust, clay, or even small bits of living things. Once a snowflake starts, it grows by taking water vapor from the air. This happens when the air is very cold and holds more moisture than usual.
As snowflakes grow, they often form pretty, branching shapes. Most snowflakes look white because their many tiny parts scatter all the colors of light. Even though snowflakes are often shown as perfect stars, each one is unique. This is because of the many water molecules that make it up. The shape of a snowflake depends on the temperature and humidity where it forms, which is why no two are exactly alike.
Classification
See also: Classifications of snow § Snow crystal classification
Snowflakes come in many beautiful shapes. Scientists say that each snowflake is usually unique, but some similar ones can be made in labs. The shape of a snowflake depends on the temperature and moisture where it forms.
In warmer freezing air, snowflakes are thin and flat. In colder air, they can look like hollow columns or needles. In even colder air, they become flat again, often with branches. Experts have identified around 80 different shapes for snowflakes.
| Temperature range | Saturation range (g/m3) | Types of snow crystal below saturation | Types of snow crystal above saturation |
|---|---|---|---|
| 0 °C (32 °F) to −3.5 °C (26 °F) | 0.0 to 0.5 | Solid plates | Thin plates Dendrites |
| −3.5 °C (26 °F) to −10 °C (14 °F) | 0.5 to 1.2 | Solid prisms Hollow prisms | Hollow prisms Needles |
| −10 °C (14 °F) to −22 °C (−8 °F) | 1.2 to 1.2 | Thin plates Solid plates | Sectored plates Dendrites |
| −22 °C (−8 °F) to −40 °C (−40 °F) | 0.0 to 0.4 | Thin plates Solid plates | Columns Prisms |
Use as a symbol
The snowflake is a popular symbol, especially during the Christmas season. In many places, snowflakes stand for purity and are linked to the idea of a "White Christmas." People often make paper snowflakes by folding paper, cutting a design, and then unfolding it to reveal the pattern.
Snowflakes also represent winter and cold weather. For example, some winter tires have a snowflake symbol to show they work well in snow. The snowflake has been used in the emblems of several Winter Olympics games. In Canada, a special snowflake design represents the country’s northern roots and rich culture.
Images
This article is a child-friendly adaptation of the Wikipedia article on Snowflake, available under CC BY-SA 4.0.
Images from Wikimedia Commons. Tap any image to view credits and license.