Wentworth (1922) grain size classification
![Wentworth (1922) grain size classification](https://planetary.s3.amazonaws.com/web/assets/pictures/20130116_wentworth_1922_02_f01.gif)
For more information about sediment classification, visit the United States Geological Survey website.
Here is a more complex version of the same chart:
![Wentworth (1922) grain size classification detailed chart](https://planetary.s3.amazonaws.com/web/assets/pictures/20130123_wentworth_chart.gif)
And here's a couple of classification schemes for sediment using these terms: