slightly cracked sapphire, should i worry or pay for replacement glass?

[MX793]

That doesn't look like a crack to me. Did the crystal make direct contact with the door knob? What was the door knob made of (Brass? Steel?)? Sapphire is harder than most metals. What you're looking at might actually be a bit of metal from the knob smeared onto the crystal. Some metal polish might actually be able to remove it.

[Joetex]

That doesn't look like a crack to me. Did the crystal make direct contact with the door knob? What was the door knob made of (Brass? Steel?)? Sapphire is harder than most metals. What you're looking at might actually be a bit of metal from the knob smeared onto the crystal. Some metal polish might actually be able to remove it.

I was thinking along the same lines. Perhaps its some residue from an accidental bump?

[TwentiethCenturyFox]

Fantastic watch definitely replace it.

[choochoosole]

I'd have it replaced. It's a weak point and another minor bump could cause it to shatter.

Think of it like a stone chip on your windshield. Once you have one even a relatively small temperature change or going over a bump in the road can cause it to run all the way across your windshield .

damn ok. i was able to get to casios repair site. their estimate is around $150 shipped to the east coast place in new jersey. but the west coast store called the time machine tryin to charge $380 cause they say it would be better to replace the entire case for water tightness. i feel like id rather save some money and go with the official east casio facility. what do you guys think?

[choochoosole]

Originally Posted by MX793
That doesn't look like a crack to me. Did the crystal make direct contact with the door knob? What was the door knob made of (Brass? Steel?)? Sapphire is harder than most metals. What you're looking at might actually be a bit of metal from the knob smeared onto the crystal. Some metal polish might actually be able to remove it.

really? didnt even think of that one. it did actually hit the door knob. i dont think its a brass door knob.

[sticky]

Try and determine whether or not it’s a scratch or a deposit off the door knob. If it’s a deposit then you should be able to polish it off but it it’s a scratch it represents a possible weak spot so I’d have the crystal changed.

[murokello]

Of course it is not deposit from a door knob. Watch sapphire crystal is smoot and there is nothing where the metal from the door knob would stick to. That mark is a scratch. Scratches to a sapphire can occur when you pump it to concrete, rock minerals, plain sand, even hard hit to a sharp metal in a right angle.

[MX793]

Of course it is not deposit from a door knob. Watch sapphire crystal is smoot and there is nothing where the metal from the door knob would stick to. That mark is a scratch. Scratches to a sapphire can occur when you pump it to concrete, rock minerals, plain sand, even hard hit to a sharp metal in a right angle.

When a harder material is rubbed against a softer one, regardless of how smooth the surfaces, you can leave a deposit from the softer onto the harder. If you couldn't leave deposits on smooth surfaces, then how is it possible to write on glass with crayons or lipstick? I smacked my watch into a painted metal railing a few months ago and saw a mark on the crystal and panicked. Then I rubbed it with my fingernail and realized that the mark was dark gray paint that had rubbed off onto the crystal. No damage to the watch (well, tiny scratch on the bezel...). Sapphire is harder than most everyday substances. Certainly harder than the materials typically used for door knobs (usually brass, bronze, or stainless steel... all relatively soft metals and much softer than sapphire). You might be able to chip sapphire with a sharp metal implement, but to scratch it you'll need something like a higher grade hardened steel (like what metal cutting tools are made from). I can pretty much guarantee that you can take any stainless steel piece of flatware or cooking utensils in your house and none of it will be able to scratch a sapphire crystal regardless of how sharp. If you chisel at it, you might be able to chip it, but more likely you'll just shatter it. What was pictured was not a chip. And given how sapphire in a watch is press-fit and is very brittle, I really really doubt it's a crack. The crystal would more likely have shattered. At a minimum, the crack would have rippled across the entire sapphire, not be isolated to a millimeter.

Plain sand is silicon dioxide, which is softer than sapphire. You cannot scratch sapphire with silica. If the sand has some corundum or other harder elements mixed in, maybe. Concrete might have some harder minerals mixed in it (including corundum) which might be able to scratch sapphire. Same with some sedimentary rocks.

[Chaos_meme]

That’s a scratch. Leave it alone.

I bet there is some material transfer between the doorknob and the crystal. Take a pencil eraser to it and try to rub some of the transfer out. The scratch will still be there but less noticeable as it will hold less foreign material.

You’re more likely to chip it than crack it