I recently obtained my first Omega and saw this spot I need it off! Since I can only find my info for the watch off of eBay auctions I can't find out what the crystal is made of. I think it is from around 1980 and is a cal 1351.

 

That's either tempered mineral or sapphire. If the spot you refer to is dirt, I suspect it might be on the inside, or you probably would have cleaned it off by now. It it's on the inside, that's a colour of another horse. The case will need to be opened, and the movement removed. If the mark is a scratch, whether he crystal is tempered mineral or sapphire, you'd be best replacing it rather than trying to polish it out.

 

Yeah I am pretty sure it is a scratch. I can't seem to find a replacement crystal where would I look?

 

What are the numbers inside the case back?

 

My

 

Crap pics, but managed to try enough numbers to get a result...

063TN5325 | GLASS MINERAL D28.5 H0.8

Mineral crystals are the worst of both worlds between sapphire and acrylic. They are much easier to scratch than sapphire is, and much harder to polish than acrylic, so your best bet is a replacement. The good thing is they aren't expensive, and Omega still makes them. If you can find one it will also require a new crystal gasket.

Hope this helps.

Cheers, Al

 

Helps a lot! Thank you