Is the jewel name sapphire, ruby, diamond on these movements an indication of grade and which is highest and lowest? I am assuming that ruby is a higher grade than sapphire, but we know that assumptions are sometimes dangerous.

Yes, these are grade names for the better of the 6/0 size movements. 1911 and 1917 catalogs list four grades: Diamond, Riverside, Ruby and Sapphire. A 1921 catalog only lists the Riverside, Sapphire and a 7-jewel unnamed model. In addition to wrist and pendant watches these were also the movement for the stylish and thin Opera Watch.

The "Diamond" grade has 17 jewels and was the highest grade in the jewel series. It was also produced marked both "Diamond" and "Maximus". It has a gold train, gold jewel settings, diamond endstone and was probably position adjusted. The later "Emerald", although more highly jeweled (21) does not have anywhere near the finish of the Diamond or Maximus.

Next in line, below these, are the Riverside (17j with gold settings), the Ruby (17j or 15j) and the Sapphire (15j), in that order. There were also some unnamed grades (7-15j) in this size, but although 6/0 I suspect may not have been considered "jewel series".

Jerry, I had the impression from a previous discussion that the Diamond Maximus may have only been used in the Opera watches. Is my recollection correct. I have never seen one in a wristwatch or a regular case.

By the way in preparing for the Seminar this weekend I was reviewing Ezra Fitch's patents and found the patent for the Opera Watch:1084880, Jan 20, 1914.

I'm not sure how we could demonstrate the original use of the Diamond-Maximus. I have seen two turn up on eBay cased as wristwatches (one in a Dennison case) and one as a pendant. They are coming from both open-face production (listed as Opera), and hunting production that is shown merely as Diamond in the gray book. The wristwatch from the run listed as Opera may be a recase, but how do you prove it (although an open-face movement cased as a wristwatch is suspicious)?

Thanks for the information. I have a 15-j ruby in a Wadsworth wgf case marked with J.S. just above Wadsworth in the case back.

Jerry,

The hunting example seems to refute the "Opera Only" theory.

Thanks.