Rep Jewels!

[14060 or 16610?]

Maybe this has been discussed before; if so, my apologies in advance. I come from the gen world and don't have much experience with this.

I was recently servicing an A7750 that had all sorts of issues. During disassembly I discovered the jewel for the great wheel was shattered, pinched between the driver cannon clutch and the great wheel. I only found 2 pieces, leading me to believe it was broken during assembly. The first thing I did was inform the owner. Then I pressed a replacement jewel out of a parts movement and installed it, and everything is running nicely now.

A couple days later I was taking a closer look at the fragments and tried breaking one with a screwdriver. To my surprise, it split rather easily. I tried again on one of the resulting fragments, and it pulverized into dust without any difficulty.

I obviously have experience with pressing and working with jewels, both intact and broken. This "ruby" was actually just pink colored glass. No way it was a 9.0 on the Mohs scale. Remember, ruby is essentially pink-colored sapphire (like the crystals on most of your watches) and is extremely hard and very difficult to even scratch, let alone pulverize. Sapphire is the material used in the counter-mount bar code scanners at your local retail store; cans, foods, hardware, tools, etc. are all dragged across it all day every day for years and months with little effect. That's because only moissanite and diamond are harder on the Mohs scale.

Still haven't decided whether or not this is a bad thing. My first instinct is that this shouldn't be a problem if proper lubrication is present, but I have to give this some serious thought. Just be aware of this new feature.

 

[Fiddo]

First time I have seen this. I guess I just assumed that the jewels were what they claimed to be....call me naive, I guess? After thinking about it, it really doesn't surprise me. But, there is a bit of disappointment.

 

[jmd33]

I, for one, am shocked!!!!

j/k

Thanks for the heads up.

 

[trailboss99]

Yup, not surprised in the slightest TBH.
Those Chinese!


Col.

 

[GC]

Surprised...i am not.

 

[DenfromNM]

Well the most rubies are not even natural stones, more than likely they are synthetic on a gen watch also. So doesn't surprise me either.

 

[14060 or 16610?]

Well the most rubies are not even natural stones, more than likely they are synthetic on a gen watch also. So doesn't surprise me either.

Just about all rubies in modern watch movements are synthetic. There's nothing wrong with that at all, as the properties of the synthetic - most importantly the hardness - are nearly identical to the natural. In this case, it's not even a synthetic ruby. It's a piece of pink-colored glass.

 

[optical]

that is shocking, to even fake the godamn ruby!? Just makes me wonder if this is a new thing or have they always been like this..

 

[levelmanroger]

The more I read the less I like reps.

 

[alvinado]

that is scary g... no good, is it a high beat or the low beat 7750?

THe highbeat from the hublot is from seagull, I am sure seagull will not use glass?

 

[Alpha Dog Omega]

Interesting to know.. not much most of us can do about it though... sadly. But I do trust the Chinese to put higher quality glass in our most expensive reps... that would be the only descent thing to do, so I'm sure they are.

 

[polaris]

I am sure manufacturers would do whatever they could get away with. Let's not forget other ingenious switcheroos such as:
"Chinese Cooking Oil Made from Sewage"
"Chinese bridge made from rubbish collapses"
"Chinese Building collapses.. Intact!"
"Chinese soup made from rubbish"
"Chinese boost milk protein.. with melamine"
"Chinese sewage celery"
google go!
:jerry:

At least it's glass and not plastic.

14060 you have inspired to destroy a movement I have.
I have a spare a6497, the cheaper stickered kind missing a part.
Two jewels shattered when I ham fisted them out [using a small screw and a flat surface] one came out complete.

Tried to crush them with a screwdriver but they seemed pretty hard. Could only split the finer fragments. In the end still have nfi sapphire or glass. So I don't have much to add

But if they are glass, I imagine that un-oiled movements would deteriorate faster. true? [Edit: faster than a sapphire jeweled movement. As in the dry metal on glass, scoring the glass...]

 

[lexxdiamondz]

you would think they would put lead in it, like they do everything else...

 

[Francisco]

I think there is a logical explanation. However, my poor English is not helping me to show it.

Jewels are resistant to wear, they are hard. But they are fragile. Once one jewel is broken is easy to break it up more times.

Why? Because the cracks on the surface of the jewels are producing a lot of stress in a very small area.... in the end of the crack. I remember I studied this is my career...

This could be an explanation, or they are really glass... but price of jewels is very low. I have just bought a replacement jewels set (100 pieces) for less than 5 euros, from Cousins:

so I guess they cannot save money with this approach (glass).

regards,

Francisco

 

[14060 or 16610?]

I think there is a logical explanation. However, my poor English is not helping me to show it.

Jewels are resistant to wear, they are hard. But they are fragile. Once one jewel is broken is easy to break it up more times.

Why? Because the cracks on the surface of the jewels are producing a lot of stress in a very small area.... in the end of the crack. I remember I studied this is my career...

This could be an explanation, or they are really glass... but price of jewels is very low. I have just bought a replacement jewels set (100 pieces) for less than 5 euros, from Cousins:

so I guess they cannot save money with this approach (glass).

regards,

Francisco

Hi Francisco,

Your English is very good. I understand what you are saying.

I also buy jewels and know they are not expensive (unless they are for Rolex of course). So the makers would not save much money, I agree.

I have much experience with broken jewels. I know how broken jewels crack easily, but they do not crumble into powder with very little force like this one did. It was definitely pink glass.

 

[Dr.Verylong]

This really scares me. They have nil conscience. And even the dealers will be helpless in this case because from the outside it looks ok.

 

[deloreandmc]

well guess its time to keep to quartz!

 

[14060 or 16610?]

This was in a 21,600 A7750 in an IWC Spitfire. I believe the owner said he has had it for a few months; I know it is not new. He said it never kept good time. That was an understatement; the tick pattern was all over the place on the analyzer. I couldn't tell it was a 21,600 until after the service. As a side note, his watch had 1/2-inch long metal shavings inside the movement as well. I'm amazed it even ran.

 

[pilworx]

Tried to crush them with a screwdriver but they seemed pretty hard. Could only split the finer fragments. In the end still have nfi sapphire or glass. So I don't have much to add

But if they are glass, I imagine that un-oiled movements would deteriorate faster. true? [Edit: faster than a sapphire jeweled movement. As in the dry metal on glass, scoring the glass...]

this is indeed most disturbing. if they are indeed glass, is this not almost completely unusable; the metal pivot point of a gear constantly grinding against a piece of glass would assuredly be cutting through the glass in days i would imagine, at least in a few weeks anyway. in this case, metal on metal would be better as that would last longer than glass.

someone tell me this isn't so.

 

[14060 or 16610?]

It is tragic that I did not hang onto the pieces; they were accidentally discarded when I swept off my bench after the service (anal retentive habits die hard). I spent an hour on my hands and knees but came up emptyhanded. The piece was most definitely glass. It crumbled like a piece of extremely hard chocolate. You could almost "smear" it, if you know what I mean.