Potassium ferricyanide is commonly used in cyanotype printing. Unlike what the name suggests, it's not particularly dangerous.
It's also very easy to grow blood red crystals with it!
I dissolved a bunch of potassium ferricyanide in water to create a very dark brown solution. After a few days, small red crystals started forming. The final crystal looks like this after a few weeks.
While there's not much you can do with the crystal, it does 1) satisfy some primal urge for mineral collecting, and also 2) never fails to impress my friends.
If you're into cool niche hobbies, you might like r/crystalgrowing :)
![image showing [OC] I grew this potassium ferricyanide crystal at home](5fcbbf48-7bbb-5e99-9d24-6ed98ca74180.jpg)
crystalchase21 on January 31st, 2026 at 16:22 UTC »
Potassium ferricyanide is commonly used in cyanotype printing. Unlike what the name suggests, it's not particularly dangerous.
It's also very easy to grow blood red crystals with it!
I dissolved a bunch of potassium ferricyanide in water to create a very dark brown solution. After a few days, small red crystals started forming. The final crystal looks like this after a few weeks.
While there's not much you can do with the crystal, it does 1) satisfy some primal urge for mineral collecting, and also 2) never fails to impress my friends.
If you're into cool niche hobbies, you might like r/crystalgrowing :)
shutterbug1961 on January 31st, 2026 at 16:30 UTC »
that is very striking and the colour is beautiful just the thing for my new warp core lol
Kip27 on January 31st, 2026 at 16:35 UTC »
The devil’s kidney stone