Copper Crystals

2 Articles

How To Grow A Giant Crystal From Copper Sulfate

October 5, 2026 by 17 Comments

Copper sulfate crystals are probably among one of the prettiest crystals you can grow at home, with even just a simple setup with some copper scrap and vinegar already capable of producing lots of them. Yet what if you want to grow really big ones? In that case the [Crystalverse] has got your back, with a recent video that expands on an older blog post.

In lieu of the copper-and-vinegar approach you can also obtain copper sulfate directly, since it’s a common fungicide, rootkiller as well as drying agent. This means that your local brick-and-mortar retailer or favorite online store probably has a few kg of the stuff available for sale.

As with most large crystal growing procedures the key is to have a saturated solution, which for copper sulfate just takes near-boiling water, to create a mesmerizingly blue liquid if there are no contaminants in it. By adding slightly more copper sulfate there are also crystallization sites on the bottom of the jar to draw these away from your large crystal.

From there it’s the same as with growing other large crystals – even those from sugar – with a seed crystal suspended into the solution, along with a silent prayer to the crystal gods that said seed crystal continues to grow without any defects. One gotcha with copper sulfate crystals is that the intense blue color is largely due to the presence of water molecules. This means that once it dehydrates, it turns effectively white.

Also of note that is the slower the crystal grows, the better the result is likely to be. During the months that it takes for these large crystals to grow, you need to carefully manage the copper sulfate solution, remove competing crystals on the bottom of the container and keep the temperature as constant as possible.

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Growing Copper And Silver Crystals For Art

August 17, 2015 by 35 Comments

Usually when Hackaday covers electroplating techniques, it’s to talk about through-hole PCB plating. But did you know you can use the same method to produce beautiful copper and silver crystal structures?

[Fred and Connie Libby] are kind enough to share how they make their crystals that they sell in tiny glass vials you can wear around your neck. The process is simple as you would think; it’s just an electrolyte solution, with a current passing through it, depositing the metal in an ion-exchange. Rather then stop once the part is sufficiently covered, you let the process run amok, and soon large crystal formations begin to emerge. [Fred and Connie] share their technique very briefly, so if you’re looking for a more detailed how-to guide, you can find one here.

Although silver crystals are a bit out of our budget, we wonder how large of a copper crystal could be grown? Large enough to be displayed on a coffee table? Surely such a work of art and science could be an interesting conservation piece in any hacker’s home.