A little while ago I started using a quartz crystal as a prop in my photos of beads and headpins. It works quite well, most of the time, giving a sort of icy feel and adding a bit of “artistic” interest. But sometimes the crystal is a bit small, or a bit too high or a bit just-not-right. I wondered whether it was possible to grow my own crystal. A few google searches later (I heart the internet) I discovered that it’s perfectly possible, and even better, fairly simple.

Quartz crystal "prop"

Quartz crystal in a supporting role

You can make all sorts of crystals at home, for example using salt or sugar. But I am going to try to make an alum crystal. It is apparently fairly simple and safe to make, and best of all it results in a neutral-coloured crystal which is what I want in my photos. Of course, whether I can grow a crystal that has a size and shape that I can use is an entirely different matter. But the idea fascinates me, so I’m going to give it a go.

Alum (potassium aluminium sulfate) is used in all sorts of applications, for example in food preservation as a pickling agent, as an after-shave because it is a blood coagulant, and as an underarm deodorant for its antibacterial properties. Wikipedia has more information about the various uses if you’re interested.

Okay so the first step is to find some alum powder. No, I stand corrected, the first step was to find out what “alum” is in Dutch. Another google search or two later I found out that alum = aluin. And that in the Netherlands aluin comes mostly in stick or block form and is used as an (old-fashioned) after-shave. But I need the powder form which is not sold in my local drugstore.

Luckily I live really close to what passes for Chinatown here in Amsterdam and I have often found the asian grocery stores to be a great source for unusual or difficult-to-find items (golden syrup, baking soda, and food colourings to name a few). And indeed, ta-dah! I found alum powder in the spice section of my favourite asian grocery store (I’m sorta assuming that it is there for its pickling properties.)

Alum powder

Alum powder

Right, so the next step is to make my “seed crystal”—a little crystal from which I will grow my big crystal. I am going to use instructions that I found at chemistry.about.com. In essence what I have to do is make a saturated solution of alum and then wait overnight for crystals to form. Sounds simple enough. Off to give it a try.


Janet · March 26, 2011 at 16:44

Thankyou cor dropping gems embedded in your blog Jennie. I’ve been looking for a source of baking soda.This morning again ,for in some anzac biscuits.All this while I enjoy your blogging about makin g crystals.
Thanks, too for your lovely work.

jennie · March 26, 2011 at 17:11

Glad to be of service! You can even buy big 1 kg bags of baking soda in the asian supermarket, but they have smaller boxes too ;)

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