Why are cracked jewels are common on pocket watches and not wristwatches?

[dieale2]

Hello folks,

I got a Elgin movement with a couple of cracked jewels. Also it looks like I need to replace every jewel hole because all of them are horribly out of shape but that's another post.

Anyway, reading around on the internet, I noticed that cracked jewel holes are a common problem on pocket watches. However, I don't see any questions about cracked jewels on wristwatches.

I mainly work on wristwatches and I never saw a cracked jewel on any wristwatch movement. It's probably my inexperience, but it seems like cracked jewels on wristwatches don't happen that often.\

Is there something about pocket watches where the jewels are more prone to cracking? Is it something about the quality of early rubies?

Thanks,

[oldhippy]

Could be P/W's tend to be just in the pocket and get dropped. Used at work, get rough treatment. I know many are on albert chains and alike. Also years ago money played a big factor, you had lots or nothing.  Wrist watches tend to be on straps or bracelets. They wear and break but do not get so mistreated.  I don't know if I'm right or wrong.

[dieale2]

3 minutes ago, oldhippy said:

Could be P/W's tend to be just in the pocket and get dropped. Used at work, get rough treatment. I know many are on albert chains and alike. Also years ago money played a big factor, you had lots or nothing.  Wrist watches tend to be on straps or bracelets. They wear and break but do not get so mistreated.  I don't know if I'm right or wrong.

On the topic of treatment, another idea is mass. Pocket watch gears are much bigger and heavier than wrist watch gears. If you drop a pocket watch, the forces on the jewels from the pinons is going to be much larger than a wrist watch.

[TimFitz]

Like oldhippy said Pocket watches got dropped, whether from no chain, throwing your pants in the washer without going through  the pockets.  Men worked in factories which were very dangerous places. Falling or getting hit by moving equipment was a regular occurrence I would think. Especially with oily hands.  

My grandfather was a NY  Central RR cop & was killed while at work, his Hampden survived and I still carry it sometimes. 

In the last few years on the auction sites people are selling P/W's with many broken jewels and my opinion is that, inexperienced people bought them took them apart thinking they knew how to repair P/W's breaking the jewels  reassembling them. Especially the rubbed in type.

[rodabod]

Some earlier watches used garnet jewels which are very easily cracked too. 

[JohnR725]

As already mentioned garnet was popular at one time. Then if you look really carefully at your jewels notice the Sapphire in  pocket watches looks different than the modern wristwatch? Pocket watches typically have pale jewels sometimes a little mixed in color they almost always have flaws because their natural Sapphire. If Wikipedia's correct synthetic sapphires don't come into existence until 1902 with a much better process in 1916 which would mean full scale production for watches probably wouldn't occur to at least the 1920s possibly even later. Then the source of the sapphires used in American pocket watches is typically from the state of Montana which is really big in natural Sapphire production.

Then also mentions pocket watches are big and heavy and they don't like to be dropped on the floor or drops just about anywhere. Worst case hard impact of the balance assembly you lose both pivots and cracking or destroying the hole jewels and worse case I've seen cracked cap jewels.

Because natural stones tend to be naturally flawed you're going to see cracks in the stones. So what you have to do is figure out whether that natural flaw or crack is an issue? You need to look very carefully at each jewel look at the hole is it smooth even with a crack? Look at the pivots are they smooth if everything looks smooth and you don't see a problem just leave it alone. sometimes even with a visible crack the pivots are fine it depends upon the angle of crack. balance jewels you're not going to be that lucky usually if there's a crack it's going to be a bad crack other times the hole is going to be anything but round and is usually going to have sharp edges.

Then why am I advising you to keep flawed place?  on modern wristwatches typically you see a problem you just replace the part on 100-year-old pocket watch even American pocket watch that the parts were available jewels probably aren't available anymore. out of curiosity I'm looking at the 1915 Elgin parts catalog? Looks like way more of the jewels were available then I thought plus they come in all sorts of colors. The various shades of red from pale to rosy are described as Ruby, Sapphire I assume is blue then of course garnet is mentioned and for some cap stones diamond. so if this was 1915 no problem but today replacing all the jewels that's going to be an interesting challenge.

[RyMoeller]

On August 6, 2018 at 2:45 PM, TimFitz said:

In the last few years on the auction sites people are selling P/W's with many broken jewels and my opinion is that, inexperienced people bought them took them apart thinking they knew how to repair P/W's breaking the jewels  reassembling them. Especially the rubbed in type.

I second this line of thinking.  I've only done one pocket watch repair thus far and managed to crack the same jewel twice.