F35 Fighter Jet Window Sapphire Rough Chunks

These are chunks of lab created sapphire which were grown for use as sensor windows in the F35 fighter jet but didn't meet spec.  These pieces may have cracks or bubbles and may also show light pink coloration.  A couple pieces still have some of the molybdenum crucible attached.

THESE CAN BE SHARP!  HANDLE WITH CARE!!!!

This is a really cool material--lab sapphire grown for windows on the F35!  These aren't used on the cockpit but on a sensor array right below.  There are numerous sensors on the bottom of an F35 that allow for a 365 degree view in a wide spectral range.  With the incredible accelerations and speed that have to be withstood an ultra hard, ultra durable material like sapphire is needed.  But how do you make giant, flat sheets of sapphire?  Normally you'd cut windows out of a big round boule grown by HEM or kyropolis but the shape really isn't conducive to larger flat shapes.

To solve this problem Rubicon, at the time one of the nation's greatest sapphire growing companies, got a 5 million dollar grant to develop the LANCE furnace, an ultra high tech crystal growing machine that grows the world's largest flat sapphires via the "boat" method aka HDSM.  If you've ever been to a Quiznos think of the ovens with a conveyer belt they use to toast subs evenly--it's basically that but with a giant flat pan of molten, crystallizing sapphire.

Though the LANCE is absolutely incredible (we got to see it in person and meet the head crystal grower!!) it didn't have a 100% success rate, and over time the company built up a pile of defective sapphire crystals that had either been contaminated with titanium (which turns them pink and ruins UV transmission), developed bubbles, shattered during growth or usually all three.  They recently closed their factory in Chicago and auctioned off the contents, and we were able to buy the entire pile of defective crystals!  It was a dream come true!

Because some of the crystals were already shattered I've been able to start pulling one of them apart to get more manageable pieces.  These pieces can be sharp, and often have cool crystallization features on the surface as well.

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