Click to the image see a larger version (Javascript must be enabled)

This was De Boos with 2 copper, 2 nickel. It is interesting to see most of the crystals formed on the edges of the textured slab vase.

This was a Sanders glaze. I had melted copper wire with nitric acid, and added the liquid to the glaze. Most of the crystals were a rod shape, there were a few that had the usual round shape.

Same Sanders glaze with the copper wire, given a post-fire reduction to about 750 C. in a gas kiln, and some spoonfuls of old cooking oil thrown in to create a smokey atmosphere, and bring out the red colour.

This is a detail of the post-fire reduction.

This was a fun pot, made during a demo to a group of school kids. I made the narrow necked vase, placed a drinking straw in the top, and sealed it. Then sucking and blowing on the straw, the pot went in and out like a bellows. Placing a finger over the top to trap air pressure inside, the pot was dented quite firmly with a finger tip. The air pressure inside stopped the pot from collapsing. Sanders glaze, 2 copper ox, and post-fire reduction with the gas/oil. Call it a single bud vase, or an incense stick holder.

This is an interesting effect from the shape of this pot, covered with small crystals. Circles of light running around the glaze. Sanders glaze, with 5% manganese, over a slip stained black.

This clock started off as a bowl. I had drilled a hole in the centre to allow excess glaze to fall through, so not too much glaze would collect in the middle. The glaze did not run enough to fill in the hole, and the stem of a clock fitted in the hole. The glazes were multiple Sanders. Firstly a slip made of glaze, 30% clay, 4 red iron ox. and 1 copper ox. was brushed on the bowl, and bisced. The top glaze was Sanders with 5 manganese carbonate. Then Sanders with 1 cobalt ox was brushed round the rim, to about 1" down.

This had a slurry of Sanders glaze, 30% clay, and 4 RIO, bisced. Then the top half had Sanders, with 2.5 cobalt ox, followed by Sanders 3 copper ox over the lot. Post-fire reduction with gas/oil.

This unusual crystal was from Sanders, 1 cobalt ox. and some solution from copper
wire. Very few crystals on the main body of the pot. Post-fire reduction with gas/oil.

This one had the glaze-clay-RIO slurry, with some bits of steel wool included, which accounts for the streaky background. Sanders 3 copper ox. over, post-fire reduction gas/oil.

This Sanders glaze had very heavy reduction on one side.

The glaze was the slurry with 4 RIO, and Sanders 4 copper ox. over. Post-fire reduction, gas/oil.
This "spiderweb pattern" was caused by some new kiln controls for the electric kiln, which were defective. When it came to the soak periods, the temp. would drop 30 to 40 deg. C. before the power cut in again. It was in the fibre kiln, which cooled much faster than the brick kiln.

Machtey glaze with 0.5 cobalt ox. First firing not good, recoated the pot with same glaze, and fired again. I don't know why there was a brown background from the second firing.

Another nice one with Machtey 1 cobalt ox. Plenty of small secondary crystals in the spaces.

Machtey with 2 copper ox.. Same glaze as the "wood-grain", but in a different kiln, and no post-fire reduction.

Different crystals from varied soak periods, Machtey 2 copper ox. Also with post-fire reduction with gas in electric kiln. With these tall pots with the Machtey glaze, I got better results reduced with gas. Fringe benefit is that at 750 C., there is enough light in the elec. kiln that you can see changes in colour in the glaze during the firing.

Another Machtey with 2 copper ox., post-fire reduction with gas.

Another nice post fired reduction of Machtey's glaze, with 2 copper ox. and 5 rutile.

This humble little pot is now enjoying life surrounded by beautiful crystal glazes in Fara Shimbo's home.
The glaze was Sanders with 1 cobalt ox. A couple of thin pieces of copper wire were draped on the shoulders of the pot. When the wire melted and ran down the sides, the shape of the crystals changed. A post fire reduction with gas/oil followed. I tried the experiment again, with the results in the next two pictures.
Picture courtesy of Fa Shimbo

What I thought was copper wire was not pure copper. I was hoping it would melt into the Sanders glaze, with 1 cobalt ox. with a similar effect as the previous small pot.

The results of the copper wire trick. It ran a lot, but did not melt into the glaze. Whatever else was in the wire, I think it affected the glaze, as results were not very good. Even at cone 10, some of the wire did not melt at all.

I often fire different minerals in the kiln while glaze firing, to see what happens to them. Unfortunately, I put some in a crystal firing. This saucer was the closest to the specimen - I never did find out what it was, as the friend who gave it to me passed away. It never affected bisc firing, or normal cone 4 or stoneware glazes. Nearly every pot was affected - this was the worst.

This saucer was protected in the middle of a shelf. Think what may have resulted to all the other plates and saucers if I'd resisted the temptation to give the specimen the longer firing.

We don't waste a thing! Excess glaze runs collected in a dish under the pot are not wasted, if they look interesting enough. A friend did some silver electro-forming for me. The blobs of glaze can be shaped, but they don't take a polish very well - too many minute pits and crazing. And some pots going onto the shard pile may have a good crystal showing, and this could be saved for jewellery or mosaics.

This is a better view of the largest pendant.