Like a lot of members here I am sure we have watches with scratches on the mineral crystal.
I have read threads were people say it is too difficult to remove due to the hardness of mineral crystal i.e. much harder than glass. Others have said it is possible if you use diamond paste with various abrasive sizes something like 30 microns to remove the scratch and 3 microns to polish.
Always seems that there is no consensus that anything works though.
Of course we all know the old toothpaste trick that is said to work on plastic acrylic crystal but is said to be useless on mineral glass. I must admit I have attempted to use toothpaste on my mineral glass scratches with seemingly absolutely no effect. I put a little fresh toothpaste on and started rubbing straight away.
Well I recently picked up two old G Shocks a DWM-100EC and a Giez GS-500, both of which had very noticeable scratches right at the front of the crystal and it was annoying as they were not like some scratches were you have to angle the face a little to see them.
It is hard to capture scratches properly in photos but here are the scratches on the DWM. As well as the immediately visible scratches it had others you could see when the watch face is angled. You can see them above the words 'water 200m'
On the Giez, as well as scratches that were visible as the watch face was angled, it had a small mark similar to a windscreen stone chip right in the center of the crystal. You can see it just above the minute hand and to the right of the second hand.
Well I was looking round the net with the intent on getting some diamond paste and checking out abrasive qualities when I read that toothpaste is far more abrasive if it is left to dry for a bit.
So, as an experiment, I tried it on the DWM. I put a little smear on the face and left it for 15 minutes and then started to rubbing it just using my finger. You could immediately feel the additional friction and therefore abrasiveness right away. I used strong pressure whilst rubbing in a circular motion. I did this for about 5 minutes then rinsed and checked. RESULT!, there was definite difference in the scratches. Still there of course but clearly not as visible. Encouraged I repeated the process 5 or 6 times.
The end result?
All scratches gone!
Also it seems to my eyes that the crystal overall is much shinier and clearer. Possibly because those micro scratches that you cannot see have been removed.
I then tried it on the Giez. Same result all scratches gone. The 'stone chip' was more difficult but I used a cotton bud to concentrate the rubbing and pressure into that small area and it also was removed. Amazing!
I used Colgate Total but there are toothpastes out there that are more than twice as abrasive as that and presumably would work quicker. See here.......
So this is proof that you can remove scratches with just toothpaste. It is just a function of pressure and abrasiveness. Also using toothpaste, rather than some diamond cutting compound, you are not going to ruin the crystal with some too savage cutting.
So the key things are letting the paste dry for a while then using fair pressure in the rubbing action and a bit of patience.
Of course if you have a deep scratch, that catches on your fingernail then this would be a very very lengthy process. No reason why it wouldn't work eventually as the paste is definitely abrading the surface.
So folks, if it works on mine, then it will work on yours. It would be interesting if another member gives it a go and reports back.