Re: Why Always Rubies?

I have several watches with diamond end stones on the balance -- no pivot hole so just a matter of polishing a flat surface. I'm sure it's purely decorative, especially the big gaudy one that was obviously added to a late 18th century verge fussee. I've seen movements with red jewels on the plate side but clear ones under the dial. I recall reading that there was some theoretical advantage to sapphire pallet stones but I can't find the reference now. Sapphire pallets are fairly common in higher grade American pocket watches.

Jack Denver wrote:
The making of watch jewels is a highly specialized task - there are at most a handful of suppliers in Switz., possibly even just one, whose name escapes me now but iirc they are a traditional family firm and not part of Swatch (rather a supplier to Swatch). They start by making a (red aka ruby) sapphire "boule" which is a large salami shaped crystal that is grown from a "seed" much the way silicon crystal is grown for chip making. The boule is then sliced and diced and drilled and polished, etc. so that one boule is turned into many thousands of jewels in a very elaborate multi-step process. I suppose that making and stocking different color jewels would add to their costs without any improvement in function. They would probably do it anyway if the manufacturers demanded it (and in turn the customers demanded it) but apparently no one (except you) cares anymore what color the jewels are, so , ala Henry Ford you can have watch jewels in any color you want as long as it is red.

Diamond would theoretically provide more than a cosmetic improvement and some old time pocket watches did indeed use a couple of diamond jewels in key (visible) places but the slight increase in hardness is outweighed by a large increase in cost (not only the cost of the stones but more the cost of turning very hard diamond into the proper shape) so AFAIK diamond watch jewels are no longer made. There was a 50+ year period between the demise of the pocket watch and the re-emerged popularity of the glass back where the watch movement disappeared behind a sealed back and was almost never seen except by watchmakers, so a lot of cosmetic finish disappeared from the market.


"Alex W." <ingilt@xxxxxxxxxxx> wrote in message news:6lpvp8Fdlo5kU1@xxxxxxxxxxxxxxxxxxxxx

Why are movements these days exclusively jewelled with rubies?

I've been looking into buying a wristwatch recently and have narrowed down my field of candidates to two firms that offer a custom-made service (Dornbluth and Habring). However, neither of those two firms -- nor anybody else, as far as I can tell -- offer anything but rubies for their jewelling.

Having once owned -- and then stupidly sold -- an Edward Howard with sapphire jewelling, I have always found this a most attractive feature, and I cannot think of a technical reason why a watchmaker should not use sapphires. The hardness is the same, after all.

Can anyone offer a good explanation?






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