Fracture filling a citrine gemstone

Question

Long story short, the gem was dropped on a stone tile floor and cracked pretty badly. The gem was cracked on the inside before but now a few of those cracks run to the surface and a little chip can now freely move in and out. There are no parts missing, if the chip is put back, it fits perfectly and you can barely see the scratches from the cracks when reflected against a light.

The gem has sentimental value and I'm looking to fix it. I was thinking, perhaps the resin that they use for fixing windshields would work? I don't have a method to create a vacuum but perhaps if I just submerge the gem in the resin and leave it be for a few days, would the resin seep into the cracks anyway?

Afterwards I would extract the gem from the resin and place it in direct sunlight for the curing. I would expect the resin that seeped in to stay in during the curing and the rest would just drop off. After curing I might go back in with more of the resin and a brush to fill any remaining surface scratches and then even them out with a razor blade after those cure too.

Anyway, I've never done anything like this before so its just all in my head as of now, does anyone know if it would work?

Answer 1

You can try the windshield repair resin to hold the loose chip. Citrine is a form of quartz, which is the primary component of normal glass, so a resin designed to match the refractive index of windshield glass might not be visible.

I don't think it will work for an internal crack in a gemstone, though. The resin won't seep into the crack under normal conditions, even with light vacuum. As a point of comparison, there's a process for filling fractures in diamonds. The stone is placed in a chamber with a high vacuum. Then a liquefied glass of similar refractive index is introduced, and the vacuum is reversed to extremely high pressure, which forces the liquid into the crack. That kind of process wouldn't be needed if you could get a liquid into the fracture with a simple, low-tech process.

An alternative would be to try to just protect it from breaking apart. You could spray or dip it in a thinned, non-yellowing lacquer to give it a surface film, although it won't look the same as a bare gem. Another approach would be to embed it in a block clear resin.

What jewelers typically do is to recut the stone to make one or more smaller stones from the undamaged portions. It obviously won't be the same as the original, but if you can wrap your head around that, you still get to keep a form of the original, which can carry the sentimental value.

Unfortunately, there aren't great options for a damaged gemstone.