Plastic, Mineral Glass Or Any Other Stuff Vs. Sapphire

[vaccum]

Many of the pam 127/217 owners opt for a sapphire crystal with AR upgrade. I have done a few and here are some pics to compare...

Plastic, Mineral Glass or any other stuff vs. Sapphire

There is a simple water drop test that tells if the "crystal" is real sapphire or not (many claim that this test is very accurate). The test is very simple...just put adrop of water on top of the crystal to be tested and if it is sapphire the water drop should form a "bead" .....let's see the test and the results!

On the left is the common rep "crystal" On the right Davidsen Sapphire with AR

I just placed a drop of water on top of the "crystals"

After a few seconds you can see the difference the drop one on the left "crystal" spreaded all over and the drop on the right "crystal" still in a "bead" shape.

Conclusion...Plastic, Mineral Glass or any other stuff on left and Real Sapphire on right.

Thanks for looking!

vaccum

[gioarmani]

Very nice.

[marrickvilleboy]

In fact, that is not always the case.

I have a genuine tag heuer with crystal sapphire, and when i do the water bead test, it "fails" and spreads.

I feel that it is a combination of shape of the crystal and quality that produces these "pass" or "fail" occurences. I for one, feel that it is not always correct. It is more likely that a domed crystal will have this beading effect, while a flat crystal will always spread.

any comments?

[sssurfer]

Very clear and informative post, vaccum, thanks!

Just one additional hint for the noob: clean well the crystal before testing.

[Polynomial]

I feel that it is a combination of shape of the crystal and quality that produces these "pass" or "fail" occurences. I for one, feel that it is not always correct. It is more likely that a domed crystal will have this beading effect, while a flat crystal will always spread.

any comments?

I think the test would work if you compare two of the same shape crystals, the spread might be still different indicating which is which, not necessarily straightforward to tell if you compare two different shape crystals

[Guest avitt]

When I do this test, I actually spread the water around a bit with my finger. Then I lightly shake (try to vibrate) each crystal. On mineral glass, the water will spread out more, while on sapphire the water will gather into a tall, round bead (like in vac's picture). This technique helps with flat crystals.

I've found the water test to be quite reliable.

[vaccum]

In fact, that is not always the case.

I have a genuine tag heuer with crystal sapphire, and when i do the water bead test, it "fails" and spreads.

I feel that it is a combination of shape of the crystal and quality that produces these "pass" or "fail" occurences. I for one, feel that it is not always correct. It is more likely that a domed crystal will have this beading effect, while a flat crystal will always spread.

any comments?

Well here I tested a pam 177 and a Pam 036 both with "flat crystals" and the results were the same

177

036

[TJGladeRaider]

In fact, that is not always the case.

I have a genuine tag heuer with crystal sapphire, and when i do the water bead test, it "fails" and spreads.

I feel that it is a combination of shape of the crystal and quality that produces these "pass" or "fail" occurences. I for one, feel that it is not always correct. It is more likely that a domed crystal will have this beading effect, while a flat crystal will always spread.

any comments?

Crystals don't get much flatter than modern subs and SDs - I have had a couple of hundred that beaded up just fine.

Bill

[flavor flav]

very cool. thanks for the tip

[vaccum]

very cool. thanks for the tip

IWC Ingy

This is a flat crystal with the same results

[KenMc]

The actual reason the water beads up on the sapphire is because the sapphire crystals are processed (typically) to a higher level of smoothness - compared to mineral glass. The theory of electrons / molecular differences was just a theory, it's the level of polishing that makes all the difference. Microscopically, a mineral glass surface has deeper pits that 'tease' the surface tension of the water bead, causing it to want to spread out. Polish those micro pits out and a mineral glass will perform just like the sapphire in the test. Sapphire being so much harder than glass, it needs a completely different polishing process, the price point supports that the sapphire crystal makers will do a better job - by default.

Want more proof, buy a good quality camera lens filter, place a drop of water on the surface and compare to a sapphire crystal, doubt that you could tell a difference. Why does the mineral glass camera filter perform so well? it's processed to achieve optical purity, perfect flatness, just as much attention to making as a sapphire watch crystal.

I was also a early promoter of the water bead theory, but I learned more and changed my views. One point, if you want to compare, both crystals must be clean.

[vaccum]

The actual reason the water beads up on the sapphire is because the sapphire crystals are processed (typically) to a higher level of smoothness - compared to mineral glass. The theory of electrons / molecular differences was just a theory, it's the level of polishing that makes all the difference. Microscopically, a mineral glass surface has deeper pits that 'tease' the surface tension of the water bead, causing it to want to spread out. Polish those micro pits out and a mineral glass will perform just like the sapphire in the test. Sapphire being so much harder than glass, it needs a completely different polishing process, the price point supports that the sapphire crystal makers will do a better job - by default.

Want more proof, buy a good quality camera lens filter, place a drop of water on the surface and compare to a sapphire crystal, doubt that you could tell a difference. Why does the mineral glass camera filter perform so well? it's processed to achieve optical purity, perfect flatness, just as much attention to making as a sapphire watch crystal.

I was also a early promoter of the water bead theory, but I learned more and changed my views. One point, if you want to compare, both crystals must be clean.

Very good info. So if the water drop beads on top of the crystal that confirm I got a real sapphire crystal or a very good camera lens quality crystal. Thats good enough for me

Now if the water drop does not "bead" you got a bad quality crystal and definitely no real sapphire:thumbdown:

Thanks for sharing!

[vaccum]

Pam 036

[stang]

I read on timezone that there are two easy ways to tell sapphire from mineral crystal.

1) When viewed from the side, mineral crystal will have a greenish hue to the edge while sapphire will have a pinkish hue.

2) The water test. Place a large drop of water on water on the crystal ... then ... tilt the crystal so the drop slides off. On the sapphire, the drop will slide off almost completely leaving just a few very small, round beads remaining. The mineral crystal will leave a large streak on the glass.

I tried this on two crystals I have, mineral & sapphire, and it worked perfectly. Try it for yourself if you have both types.

Jeff

[avara]

Good info. Thanks.