Also, on a related note, is there a symbol for grain (i.e. the grain version of BTC)?

This would work well for tiny icons.

[addendum]

In case there isn't a symbol, below are some candidates. If a vote is in order, then voters may refer to them by the letter underneath. These are Arial font. Note that the difference between a and b is the gap between the top bar and the main curve. I think that g might run the risk of being commonplace.

My personal favorites are a and e. I think e might have promise because the "r" is reminiscent of grain, and altogether hinting to the grain logo.

Suggestions are welcome and I can design around them.

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