Solved cryptogram
Every rock is igneous, sedimentary or metamorphic, and any of the three can become another.
Earth Science Facts, sourced to U.S. National Park Service.
Solve it yourself
This fact is a cryptogram here: 74 letters over 20 different ones, graded hard.
Or go to the puzzle’s own page first.
What it means
The three names describe how a rock was made rather than what it is made of. Igneous rock froze from a melt, sedimentary rock was laid down in layers and pressed, and metamorphic rock was cooked and squeezed into something new. The categories are a loop rather than a list: a granite worn to sand becomes sandstone, a buried sandstone becomes quartzite, and a quartzite pulled deep enough melts and starts the cycle again.
The claim comes from U.S. National Park Service.
- SourceU.S. National Park Service
- CollectionEarth Science Facts
- Difficultyhard
- Length74 letters, 20 of them different
Nearby in the collection
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