Copyright © Annie Cap, Crystalline Ceramic Artist

About crystalline ceramics

Developing and working with crystalline glazes is so fraught with problems that the average ceramicist just isn't interested. It seems the true crystalliere, as we are called, is a unique sort of person, someone who is both artistic and scientific, dedicated, a bit drive if I'm honest, logical and quite passionate.  It took me 193 attempts before I grew my first crystal in a kiln, from a glaze I created, which is probably longer than some but less than others.


It's pretty common-knowledge in the ceramics industry that crystalline glazing is highly unpredictable, time-consuming and costly. This form of ceramic art carries with it an 'accepted' and even expected exceptionally high failure rate, which is a big reason why there are so few long-term crystalline potters in the world, and also why crystalline pieces most commonly appear in galleries and museums.

Even when you think you've developed a 'dependable' crystalline glaze, applying and firing it can be so tricky and finicky that sometimes it will work and sometimes it won't. Everything has to be just right. Although with years or decades of experience, you can learn to control (or encourage, is probably a better word) particular crystal colours and shapes, even growth rings and halos, you can never truly predict where or if crystals will form. They decide, just like in nature.


Macro crystalline glazing requires massive dedication and very high temperatures, too (Cone 10 or 11, up to around 1300 degrees C). Once the glaze materials have thoroughly melted, like magma in a volcano, the kiln is allowed to cool slightly into the crystal-growing temperatures (which varies for each individual glaze formula).  It's here thatthe real magic begins. If you are lucky, the crystals 'seed', creating nuclei randomly 


 

within the molten, fluid glaze matrix--and stars are born! After the nuclei have formed, the zinc-silicate molecules (now able to float and move within the melted glaze) are drawn to each other and start clinging together, first forming rods, and then, given enough heat and time, expanding like flowers, growth rings of a tree, or exploding fireworks.


Crystalline pieces also require up to four or more coats of glaze (which is usually brushed or sprayed on), and the use of individually thrown ceramic pedestals (stands to elevate the pots) and catchers (shallow bowls or saucers) to collect the glaze run-off to avoid ruining the kiln with the very runny crystalline glazes. Afterwards, the pedestals and catchers must be broken from the fired work (another chance to ruin your pieces) and the bottoms are carefully smoothed with a diamond lap grinder.


For all these reasons crystalline pottery is rather special and rather rare. It's not just about the increased effort and expenses required to make a good piece ready for firing, it's the fact that each piece you fire--only offersthe potential--to create uniquely beautiful crystalline formations.  Even when you prepare, load and fire your kiln, filled with pieces glazed just as you've done a hundred times before, crystals just may not form, or the reverse may happen and too many crystals decide to form; either way, the pieces are ruined.


Considering all the negatives, probably the only way to explain why a few of us choose to put ourselves through the extraordinary ups and downs of crystalline ceramics is to allow you to feel what we feel--when things go right. Even when there's only one exceptional beauty sparkling back at me when I open my kiln, and it's sitting amongst the broken shards of the rest of the kiln load, somehow, it's all worthwhile and thoroughly exciting.


Thank you for your interest in crystalline pottery and for your appreciation of my artistic endeavour.

 

--Annie Cap