Crown Jewel movements

[bond]

I am an alien. Jewel movement is the the undiscovered. I wish to discover its alluring mystery. Any good places to start apart from google which leaves me dribbling.
What constitutes 2824-2 jewel swiss movement and how good it is?

[docd]

It's very good - because of the enormous number of jewels in it :D

Actually AFAIK the jewels in a movement relate to pivots or bearings for the shafts of the movement to run in - a jewelled bearing reduces friction - but costs more money since the bearing material is a semi-precious stone - typically ruby (hence the jewel bit).

A good quality automtic movement will have about 25 jewels (not 2824 :wink: that's the ETA movement id number ). Excessively high jewel counts usually means decorative jewels have been applied - which don't have a mechanical function.

[wombat]

The jewels in a movement are made of artificial corrundum similar to the "sapphire crystals". White corrundum is called sapphire, red corrundum is called ruby.

Usually higher quality movements have more jewels than those of lower quality. But the number of jewels depend on the kind of construction, too. E. g. a module chrono movement based on an ETA 2892 has usually 38 jewels while the ETA 7750 chrono movement has "only" 25. The 7750 is the better chrono movement, the 2892 + chrono module has more jewels because of the module construction.

The more complicated a movement is, the more functions it has, the more jewels it needs.
The PP Sky Moon Tourbillon e. g. has 54 jewels:



On the other hand the AP 2121 movement (e. g. Royal Oak Jumbo) has 36 jewels even though it's only a simple two-hands-movements with date indication.




There are different kinds of jewels used for watches.

Jewels a WIS is interested in:


Lange rubies are mount in gold settings and screwed in the plate (the French term is chaton, but I don't know if it's used in English, too). This is taken from one of Ming's photos.


Jewels a woman is interested in:



Jewels a pimp or a Russian (or a Russian pimp) is interested in:



/ Hal