Just how do you go about "cracking" a crystal, anyway?

[SirRawThunderMan]

I'm planning a build with a cracked crystal, unstable blade, vents, etc. Not a Kylo Ren replica, just taking those elements from it and using them in a different shape. I've got ideas on how to do the unstable blade and the vents, but the cracked crystal  for the crystal chamber reveal is eluding me. There's not much out there on cracked crystals, other than "Kylo Ren's lightsaber is unstable because it has one."  Was it cracked when it was mined? Was it always cracked? Did Kylo go on a crystal quest like those kid Jedis did in that Clone Wars episode and find the one broken crystal in the cave? Or, to take that (downright stupid, I think) new canon of crystals "bleeding" red blades to the extreme, was it just a regular crystal that's bled itself so much it cracked? 

Yeah, I've been thinking about it a bit. That's all mostly irrelevant, for the time being. There's not much out there, so I figure that gives me a fair amount of artistic freedom with regards to what one should look like.

The question really is how to make a relatively small detail like a crystal look visibly cracked and unstable. Off the top of my head, I've got:

1: taking a dremel to a piece of quartz/plastic/glass (or whatever the crystal will be made of) so that, say, one side looks jagged and the other looks smooth
2: making an epoxy cast crystal with some slivers of aluminium foil inside of it so that it reflects the accent LED's light in an uneven/broken way
3: Cutting a crystal in half vertically, then binding both halves together with strips of duct tape (or Space Tape) for a really busted up look
4: messing around with the flicker setting on the sound card so that the accent and main blade LEDs are unstable (more of a general option than crystal specific)

And that's about all I've got. All ideas and suggestions gratefully accepted!

[SOSDD]

Mine is made of three small pieces of quartz glued together with super glue.

[Greenie]

Break a crystal with a hammer then super glue the prices back together.

[Darkjedi]

Finding a crystal wholesaler this way you can look at loose crystals. Lots of times you can find cracked crystals or with veins. They look interesting moving the LED to different areas of said Crystal.

Or just make your own out of resin.

[SirRawThunderMan]

Mine is made of three small pieces of quartz glued together with super glue.

I've seen sabers with crystals like that, they looked pretty awesome. Might give that a try.

[Ridire Fíréan]

Hey @SirRawThunderMan  !  You could always try the boiling/baking trick!



Take a crystal and drop it in a pot with water.

Put on SAFETY GLASSES and LEATHER GLOVES.

Boil the water.

Take the crystal out with a set of metal tongs.

Drop it in a bucket of ice water.



This trick works with glass marbles, so it might work with crystals too.

Here's a step by step that uses an oven instead of boiling water to heat the marbles...

How to Make Cracked Marbles: 11 Steps (with Pictures) - wikiHow



BE CAREFUL!  And Good Luck!  Post up your results when you can if you try this.

[SirRawThunderMan]

Hey @SirRawThunderMan  !  You could always try the boiling/baking trick!



Take a crystal and drop it in a pot with water.

Put on SAFETY GLASSES and LEATHER GLOVES.

Boil the water.

Take the crystal out with a set of metal tongs.

Drop it in a bucket of ice water.



This trick works with glass marbles, so it might work with crystals too.

Here's a step by step that uses an oven instead of boiling water to heat the marbles...

How to Make Cracked Marbles: 11 Steps (with Pictures) - wikiHow



BE CAREFUL!  And Good Luck!  Post up your results when you can if you try this.

Okay, that is awesome and I'm going to give that a try with some marbles at the weekend. My gut says that that would not work with Quartz tough, but I'll give it a go. I've got some spare somewhere.

[Ridire Fíréan]

Hey @SirRawThunderMan  !  I dunno, I'd bet since glass and quartz are both made of silicon, that it'll react similarly to heat/cold stress.  It'll certainly be easier than trying to cut or Dremel a piece of quartz!  I was getting tired out trying to sand a piece of quartz this summer and switched to trying to use my belt sander on it.  Interestingly, it took it a minute, but boy did it get hot on the sander and it took it quite some time to cool down!  Not much was accomplished on the sander before I could no longer hold onto the quartz.  In that manner, it is indeed very tough!  I even put on some leather work gloves to try and hold it, but the heat seeped right through the leather.

I'm looking forward to seeing your results!

[SirRawThunderMan]

That's true. Also, I find that quartz is dead easy to cut into. What you want to do is use a diamond coated cutting wheel on a dremel-type rotary tool, and it cuts like butter. Ideally, you'll also want to do your cutting under a source of running water, to both cool down the quartz and keep the toxic quartz dust from flying all over the place. The only downside to that is that the cut sides will have a rough appearance that you'll want to wet sand and polish, and that can be a pain if your cut crystal is small and hard to hold on to.

[SirRawThunderMan]

So, I gave it a shot, and to my surprise, it actually worked!

Also, I've just joined Flickr, so apologies if I mess up the image sharing process a little.

I tried it with both some clear marbles and a (much less clear) quartz crystal I had on hand. I just baked them in my oven at the highest temperature (gas mark 9) for twenty minutes, then dumped them into ice water.

Before:

After:

And a bit of Crystal Chamber-style illumination:

Overall impression: darn, I'm impressed!  I honestly thought the quartz would be more resistant to thermal shock than glass, but apparently not. it's a shame that I only had a fairly opaque crystal on hand to start with, as it doesn't show the cracks quite as well on camera than it does in person. That aside, I think I've got my dead easy crystal cracking method sorted. Thanks, Ridire!

[jbkuma]

I just tested it myself on a crystal that was a bit too clear to be interesting and got some interesting results.

[SirRawThunderMan]

I just tested it myself on a crystal that was a bit too clear to be interesting and got some interesting results.

Neat-o! I am a bit concerned about the cracking's effect on the crystal's overall cohesion. The tutorials/guides I read on baking marbles like this mentioned that there was a chance that the marbles could shatter or explode from the thermal shock. Wouldn't want to install one in a CC and suddenly hear some unexpected rattling if you drop your saber or whack it about too hard mid duel.

[jbkuma]

I actually "double cracked" the crystal and while I haven't given it the "hammer test" or tried to tear it apart with pliers, knocking it on my desk and applying hand strength didn't crumble it.  Quartz and glass are compositionally different and structurally very different.  Quartz is fairly resistant to breaking, which is why in high quality watches, the "glass" is made from quartz.  That being said, no two are alike.  If you have a fracture that goes along a plain you may be in trouble, but I don't think it will be an issue. 

I guess the next step is someone needs to get a couple dozen and do some testing to compare cracked crystals versus unaltered!

[Ridire Fíréan]

Hey @SirRawThunderMan  !  You're very welcome!  I'm glad that your experiment was such a great success!  The occlusions within the crystal definitely make it glow more internally.  Sanding the outer surface helps with glow too.  Full on polished would really let you see all those new cracks though.  Try one each way and see which way you prefer it. 

And yours too @jbkuma  !  Weird that your clear crystal looks "smoked" now.  I wonder how that happened?

As far as the cracked crystal strength is concerned, I wouldn't worry too much about it.  If you're making a crystal chambered lightsaber, you probably won't be going all SUPER-JEDI with it and trying to cut down small trees and the like with it.  I would think lite tapping to activate its Flash-On-Clash and even lite deuling would be just fine.

Take your experimental crystal and drop it on a vinyl covered floor.  If it doesn't shatter, you're good to go!  I wouldn't try dropping it directly on concrete, or stone, but otherwise I think the crystal will hold up just fine.  If you're not concerned about the test crystal, go ahead and drop it on concrete and see how it fares.   If nothing happens to it, you'll be wildly impressed.  If it blows up into a bazzilion pieces... you'll know that was too much for it to handle and you won't drop the next one on anything that hard.  I'd bet ya a Coke that the marbles blow up upon impact with concrete or stone though, so if you like those, don't experiment with them!!!

As far as them blowing up goes, I think that's just at the time of exposure to the cold water.  If it survived that process intact, you should be at ease that it is so.

I'm super stoked that this turned out so well for you guys!

If you experiment further with structural integrity tests, please post up your results.

[Ridire Fíréan]

Hey @SirRawThunderMan  !  One more question for you... Did your crystal crack in half or did you break it intentionally?  I just saw the caliper photos of the crystal in one piece in your flickr album and I'm wondering how it became two pieces.