Breaking an Apatite. Or: How Observation can Interfere with Experiment

So I had the brilliant idea of taking snapshots while my setter, Pierre, set an apatite into my new silver halo ring.  Dark blue sapphire outside, turquoise center, it was going to look fabulous.  Pierre has some very fancy setting equipment.  At his bench there is a huge microscope with very strong lighting that costs several thousand dollars, surrounded by lots of other smaller gadgets.  I guess you need that when you routinely set expensive gems.  Luckily, my apatite had only cost me about $20. 

Ring Inside Ring Holder

First, Pierre carefully clamped my ring into a ring holder, cushioning the outside of the shank with tissue so wouldn’t get marred.  The ring has to sit tight in order for the pressure from setting not to dislodge it.  Then Pierre separated the double prongs.  During casting, prongs that sit close together often have metal in between them, and it is cut apart with a separator disc.  Then the prongs are shaped into claws and the seat is drilled: that’s a little groove on the inside of each prong where the girdle of the gem will rest.  I like my gems set low, and the apatite fit perfectly into the opening.

Separating the Prongs

Unfortunately, the lighting of his microscope was so strong that my iPhone couldn’t cope, so I asked Pierre to lower it.  Which he promptly did, but not without mentioning that he could no longer really see what he was doing.  I should have taken that as a cue.

Having placed the apatite into the ring, Pierre proceeded to push the prongs over the gem with his metal bezel pusher.  

Pushing the Prongs over the Stone

As a final step, he rubber wheeled the prongs.  This means sanding them down with a soft rubber disc so that the places where he marred the metal with the bezel pusher – something which is unavoidable – are filed back out.  Normally this is the tricky step because you don’t want the rubber wheel to scratch the stone. 

Rubber Wheeling the Prongs

As it turned out, in this case, the moment during which the little apatite incurred major damage was minutes earlier.  It happened shortly after the light was turned off in order to accommodate my iPhone.  Ahem.  The third photo shows you approximately when Pierre chipped it. 

Long story short, my apatite didn’t live.  And now there’s a pretty tourmaline in the center of that same ring.  So that’s how it goes.  Apatite is risky business.  With a sapphire, this would probably not have happened.  But from now on, I’m not going to ask Pierre to work in the dark! J

Chip in Girdle on Right Next to Where the Prong Would have Been (Plus Scratches You Can't See)