“Sand” means something different to me than it does to you, probably

Posted By Emily Lakdawalla

2013/01/24 01:28 CST

I had one of those “A-ha” moments last week where I suddenly realized that I had run afoul of a common problem in science communication: when the words I’m using mean something different to me than they do to almost everyone I’m talking to. The confusing word of the week: “sand.”

How can the word “sand” possibly be confusing? Well, the situation is a lot like the one with the word “rock,” which I talked about in this blog entry. Just as with “rock,” for geologists, “sand” has a definition that is far more precise than the way that the word is commonly used in conversation.

Geologist Chester K. Wentworth defined “sand” in a publication in 1922, along with “gravel,” “silt,” and “mud.” Sand-sized particles range in size from 63 microns to 2 millimeters. Gravel is anything larger than that; silt and mud are finer. When we think about sand, we usually picture quartz sand, because that’s what most sand is made of on Earth. But the term “sand” does not specify composition, it only specifies grain size. So you can have gypsum sand like at White Sands National Monument, or olivine sand on certain Hawaiian beaches, or any other composition where mechanical and chemical weathering bust rock of any composition into sand-sized particles.

Read more: "Sand" means something different to me than it does to you, probably | The Planetary Society.

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