Pyrine

Might also try graphite crucible for your experiment, are you melting the potassium down in an inert environment?

my boric acid reverts back to crystalline structure when the denatured alcohol evaporates, considering it's an old topic idk if this helps ya out any, but this method is less dangerous than the ones discussed.

Ceramic crucibles have heat tolerances, as long as he preheats the crucible before adding the antimony to melt he should be fine. We use them to melt platinum in, which has a significantly higher melting point than antimony. If you'd like I can provide several places where you can purchase them from, they'll contain anything up to about platinum, but no higher, past that you must use graphite or a special plaster of Paris investment mix for ultra high temperatures, course with the mix you gotta make your own crucible, but it isn't impossible to do.

I'm not sure how your set up is, but you would need to heat the antimony up to melting point before adding the bismuth or you'll end up burning it. I'd recommend doing it in either a ceramic or graphite crucible and making the bullion from that.

Dunno if it fits the description or what you're looking for exactly, but there are quite a few gemstones that are transparent and even clear as quartz that contain iron as part of their overall chemical compounds. Phosphophyllite is a mineral with a hardness of 4 out of 10 on the Mohs scale of mineral hardness. These Monoclinicly structured gems are made of hydrated zinc phosphate, their full chemical compound being Zn2(Fe,Mn)(PO4)2.4H2O. - See more at: http://gem5.com/stone/88/phosphophyllite/#sthash.c6rVabih.dpuf

*date pick up line* "does this smell like chloroform to you?" I swear we will be seeing someone on the news soon if yall keep given em ideas... XD

As a jeweler I have made both of those. However the hue of blue for a gold/indium alloy is fairly light, if you're looking for a deeper blue, you may wish to mix the gold with iron and then heat treat it. Also for casting of the purple gold, it is extremely brittle, so I wouldn't make an entire ring out of it if I were you, unless you are fine with it potentially shattering on you, kinda like how hematite does. Do note too that most of these colors are gained when making the purity around 22 to 18k and all the ones I've made have been used for inlay and accent to other metals. For immediate casting, you're gonna want to do it in an inert environment, I'd recommend argon, it's what I use, along with an induction or electric arc forge. You can find instructions on YouTube for making the forge, simple set up and design. I've got one built on the inside of a rocking table with a bell jar in place for my electric arc casting chamber. Only costed about 1500 to build give or take. I'm actually in the midst of attempting to create a true red gold for the same purpose as the other colored variants. I'll be producing black gold within two months, you all are more than welcome to follow my progress, just send me a pm I'll link ya where it's gonna be.