Sometimes they have a similar color and relief to garnet, with a dark border.
![](http://blogs.nvcc.edu/mineralogy/files/2018/01/air-bubbles-annotated-1024x768.png)
Sometimes they look like thick black rings.
![](http://blogs.nvcc.edu/mineralogy/files/2018/01/solo-air-bubble-annotated-1024x768.png)
![](http://blogs.nvcc.edu/mineralogy/files/2018/01/solo-air-bubble-xpl-annotated-1024x768.png)
Sometimes you get a plague of them.
![](http://blogs.nvcc.edu/mineralogy/files/2018/01/50HD3992-1024x768.jpg)
Sometimes you’ll see a mineral with a really interesting extinction pattern. Nope. Air bubble.