20th c American Jewel Material - Garnet or Ruby?

[BobbyMacStevenson]

I was flipping through some old Illinois Watch Co. material catalogues recently and found the replacement jewel section.

All are listed as ruby or sapphire in either brass, composite or gold settings.

This gave me an idea and I took a UV light to one of my Illinois watches, as ruby fluoresces under it.

Nada. No glowing.

Although I’ve struggled to find a materials catalogue for them, what about Waltham?

Still nothing.

South Bend jewels do glow, even their lower grades.

So, this bring me to a question: If only ruby and sapphire are listed as replacement jewels (for Illinois, at least), why don’t the jewels in my Illinois or Waltham glow under UV light like South Bends?

 

[Jerry Treiman]

The age of your movements may make a difference. I believe the companies used more garnet in their earlier years, particularly on lower-grade movements. As synthetic ruby and sapphire became more prevalent these harder stones were used more often. My Waltham material catalogs show mostly ruby jewels, but garnet was used for roller jewels and pallet stones in some instances. I seem to recall reading that garnet pallet stones were usually paired with brass escape wheels and sapphire (and presumable ruby) paired with steel escape wheels.

... why don’t the jewels in my Illinois or Waltham glow under UV light like South Bends?

Could it be that the jewels in your Illinois or Waltham are thinner jewels than used by South Bend? A less massive stone might have a lighter fluorescence that is harder to detect.

 

[butlercreek]

I understand the older Bunn Specials used actual Ruby’s……

 

[BobbyMacStevenson]

The age of your movements may make a difference. I believe the companies used more garnet in their earlier years, particularly on lower-grade movements. As synthetic ruby and sapphire became more prevalent these harder stones were used more often. My Waltham material catalogs show mostly ruby jewels, but garnet was used for roller jewels and pallet stones in some instances. I seem to recall reading that garnet pallet stones were usually paired with brass escape wheels and sapphire (and presumable ruby) paired with steel escape wheels.


Could it be that the jewels in your Illinois or Waltham are thinner jewels than used by South Bend? A less massive stone might have a lighter fluorescence that is harder to detect.

The movements ages are 1898 (Waltham, 11 Jewel) 1910 (Illinois, 15 Jewel) and 1913 (South Bend, 15 Jewel).
Not much of a gap between the Illinois and South Bend, age wise, and both are 15 jewel.

I also had a look at another, older parts Illinois I have made in 1889 (also 11 Jewel), and still no glow on the jewels.

I highly doubt the South Bends Jewels are thicker than the others, as I had to replace several of them because they were cracked or outright shattered (lower balance hole and cap Jewel) despite the movement being in good shape otherwise.

 

[gmorse]

Hi,

I believe that the first synthetic rubies to be produced on a commercially viable scale were those made by the Verneuil process from 1903 onwards, although they had been made in labs experimentally much earlier from the 1830s by several workers in this field.

Regards,

Graham

 

[Dave Coatsworth]

I also had a look at another, older parts Illinois I have made in 1889 (also 11 Jewel), and still no glow on the jewels.

Your 11 jewel Illinois very likely has garnet jewels in the top plate. (I'm assuming it is an 18 size, given the date.) Indeed, the 1923 material catalog shows plate jewels for the 18 size being available in Red Ruby, Pale Ruby and Garnet. Also, many of these 11 jewel 18-size movements, such as the grade 101, used unset, burnished in, jewels, which are not shown in the material catalog. I expect that these are garnet, as well.

 

[BobbyMacStevenson]

Your 11 jewel Illinois very likely has garnet jewels in the top plate. (I'm assuming it is an 18 size, given the date.) Indeed, the 1923 material catalog shows plate jewels for the 18 size being available in Red Ruby, Pale Ruby and Garnet. Also, many of these 11 jewel 18-size movements, such as the grade 101, used unset, burnished in, jewels, which are not shown in the material catalog. I expect that these are garnet, as well.

Yes, I did figure that these ones would have been Garnet because if it lower quality, but a check never hurt.

The 1910 Illinois and 1913 South Bend are both 12 size (I should have specified this earlier, wasn’t thinking) and there is no mention of Garnet Jewels for 12 size Illinois’ in the material catalogues - but the jewels don’t glow while the South Bends do.

That’s what’s got me so puzzled. They should glow like the South Bends but do not.