Up till now - I haven't really played too much with using colored CZs in lampwork. (If I want color - I just put a dot of transparent color over the encasing.) Lately - I have been experimenting with using larger and larger CZs, and with not encasing them, to great success.
I have been using 4 mm Round CZs, unencased, and they have been working fine. Sorry - can't show you pics - it's a top secret project.
I did try a 10 mm heart CZ - and I could successfully make an impression in the glass - but couldn't get the stone hot enough to stick and couldn't find my tweezers to pick it up and place it in the depression. Note to self - always make sure the fine tweezers can be found before starting in with the CZs.
I'm pretty sure that gluing the stone into the hole it left will work. As soon as I pull the bead and clean it - I'll show you that one.
However - what I did want to share with you is that I thought I would try some colored stones. I decided to try some Aqua colored CZs. Aqua is one of the trickier to make CZs - and consequently - highly expensive - more so than regular colors. I read Heather's test of the same CZs for firing - and how they went brown. Additional testing however revealed that they retained their color when fired in activated charcoal to reduce oxygen. Interesting. So - encasing perhaps?
This was the first test subject. On the side that I did not encase the CZ - sure enough - it went slightly greenish/yellowish.
On the other side, immediately encased - it retained it's colour. They are not a very strong aqua colour - so they tend to look clear. Except that I think they show up better on the clear glass than if they were actually clear.
Here is a another spacer - the brownish smear is a reflection from a CZ that burned (reduced?) on the other side of this bead.
Here is the good one and the discolored one, side by side. The discolored one went on at an angle and had the edge poking up, unknown to me, until I saw the colour change. It's actually not inherently un-attractive.
More success with the second spacer - although you can see that I didn't get them all encased quite quickly enough. There is a hint of discoloration.
So - aqua CZ's need to be encased right away if you don't want them to turn into amber CZs. ;-)