All About Watch Crystals - Watch and Learn #2

In this second episode of Watch and Learn, we will discuss the 3 types of crystals you find on today's wristwatches, discuss the pluses and minuses of both, and give a water droplet demonstration that can help you tell the difference between mineral and sapphire crystals.
Links to items discussed in the video:
Poly Watch for cleaning plastic crystals: www.polywatch.d...
Some diamond suspension products used for polishing mineral and sapphire crystals:
www.dmtsharp.c...
Aftermarket watch crystals and presses:
www.esslinger.c...
www.ofrei.com/p...
longislandwatc...

[@hyperchord]

Him and his fiancé were "holding hands," sure . . .

[@Sparks52]

Well done on the crystal materials. Some years ago from the late 1960's through the 1980's Seiko coated the acrylic crystals on some of their upper end lower tier and their mid-tier watches with a material that hardened the surface to nearly the same as mineral glass. Seiko had a proprietary name for it that I've not been able to find. I've got two vintage Seiko with this crystal material. They cannot be polished like standard acrylic or Hesalite and are extremely durable and scratch resistant, looking just about like they did when new 35-40 years ago. They were overtaken by Seiko's Sapphlex (a sapphire coated hardlex) and Hardlex when those became economically viable for the upper end of lower tier watches. Sapphlex similarly was discontinued as the cost of sapphire dropped. There is a reason for acrylic and Hesalite being used on military watches. Unlike mineral glass and sapphire, it doesn't shatter. It can be scratched, chipped and gouged, but it's much more difficult to crack or break compared to mineral and sapphire as it flexes on impact. In addition, they're easily molded with a dome shape eliminating the mirror effect a dead flat crystal has which is a light and reflection discipline killer They've got a duller surface finish even when new that reduces the specular highlights under sunlight and other strong light sources.

[@ballsdynamite]

"PolyWatch, it looks like toothpaste, smells and tastes like toothpaste, cleans my teeth, again just like toothpaste."

[@2TheAbbeyClinic]

Another great instruction vid from you. Thanks. Can't believe this is free, like going to college for watches.

[@islandwatch]

Haha, I'll take your college savings money :)

[@c.toobitz7566]

This series is gold, thank you so much. I always wanted to learn about watches, but not on a professional level, just as a hobby.

[@RonaiHenrik]

7:25 Hmmm please correct me if I am mistaken but normal glass is more shatter-resistant than sapphire due to it being less stiff (lower number on Mohs scale of hardness). Sapphire is harder, more difficult to scratch, but because of this reason it shatters easier too, it's not as good in putting up with vibration.

[@yasyasmarangoz3577]

I think you're right...

[@2DRINKSMINIMUM]

do the different types of leather for straps! or just the different types of straps.

[@islandwatch]

Okay. There's a Horween video coming out soon.

[@2DRINKSMINIMUM]

thanks, Marc!

[@anishabisht4213]

Have you done it?

[@roadshowautosports]

I’d assume one shouldn’t buy a watch that has a sapphire Crystal cracked, since it takes a really hard hit to break them, and would be very possible damage to the movement, do you agree? Awesome video, with simple language.

[@allenjanes5976]

thanks. I found the water test most interesting.

[@islandwatch]

Pretty cool, right?

[@bassfishingwiththeantichri2921]

So what you're saying is to take heed from your friends painful tale of woe and always be sure to have a "no diamonds" policy set forth prior to engaging in any type of physical activity that may endanger the sanctity of your sapphire crystal. It sounds reasonable to me. Will do!

[@islandwatch]

LOL!

[@gunslinger11bravo]

the Russian made Vostok Amphibia 200m divewatches use a domed plastic crystal that is actually designed to increase the water resistance of the watch. As depth increases the crystal deforms and actually presses harder on the gasket underneath it. this along with a similar method used on the screw-down case back allows the watch to become more water resistant the deeper it goes.

[@islandwatch]

Great observation. Sort of like how an arch is the most efficient engineering structure. A dome is just a 3 dimensional arch.

[@neilcampbell4833]

All mineral glass will scratch eventually, quartz in dust is the worst offender for the scratches it's unavoidable .

[@munawarhussain9859]

great video very informative ........other video suggestions type of moments auto,manual wind,solar powered.quartz, kinetic. or another suggestion watch types dive,flight dress, field................love your content .

[@islandwatch]

Thank you. Great suggestions! Noted.

[@theguardian3431]

I always thought mineral has more impact resistance than sapphire, but the latter has greater scratch resistance.

[@misterman1371]

It does

[@danielpinto1221]

Sapphire brokes easily

[@Claus-L.Mueller]

Very interesting. Especially the "Lotus Effect". The only disadvantage of sapphire is it's brittleness. It's very scratch resistant but it's likely to crack if it hits a hard surface.

[@Sparks52]

I've found sapphire to be extremely durable. They're generally made thick enough to withstand some impacts during normal wear. They can be gouged or chipped if banged against a very sharp and hard object. They can be shattered, but all the watches I own with sapphire would have to be hit extremely hard to shatter the crystal.

[@yasyasmarangoz3577]

18 minutes and it completely was worth my time! I lowkey hoped that you'd destroy them to show us how resistant they're, but you've probably payed for them so I can understand it...

[@JimboJones2022]

I'm trying to get a green crystal replacement for my milgauss. I am looking for the best quality and closest to the gen without purchasing through rolex.

[@tjkeller6109]

Just started looking into collecting and I know nothing about watches. The first two videos are great and will continue watching and liking the rest. Thank you for the work you put in.

[@kennedymcgovern5413]

OK, so you say you read everything. I'll take you up on that with a question, if you don't mind. I am looking at a vintage Rolex. But, of course, it is going to be a process authenticating it. I believe it to be a 1956 Submariner. Now, it has a crystal that the seller says is "plexi glass." OK, well...I know they weren't using sapphire back in 1955. But it would seem to me that they would have, at least, used glass...being Rolex and all. I don't know,. I am learning as I collect. I remember my Father telling me that, playing football in the 50s, he got his first plastic helmet in college, which would have been 1959 for him. From this, I know plastic was new in the 50s. So...around what year did it become popular for watch manufacturers to make the move from glass to acrylic? I am still surprised that Rolex followed this trend, but...generally speaking...they had to have been glass before they were plastic so...around when did this shift occur?

[@HouseholdDog]

They put plastic on a datejust? Talk about cheapskates.

[@acat6821]

A long time ago yes.

[@Daud76]

Back in the day when plastic on Rolex was all the rage. This was decades ago. 😄

[@talhaahmed290]

2018??? Anyone??

[@godchi1dvonsteuben770]

BTW, he mentions in the video that acrylic is the oldest type of Crystal. This is incorrect. Wristwatches were invented in Switzerland, in the 1860's. Nearly 50 years before the invention of plastic.

[@murph8411]

Yes, that was a weird thing to say. More than surface scratches can be removed from glass as well. People used to, and some still do, grind glass lenses by hand. Silicon carbide can be used for rough work then the likes of cerium oxide can be used for polishing.

[@PukaHeadMan]

That Sinn is a killer watch! Great informative video. Thank you for posting!

[@yourdata2478]

Another very informative video thanks for the time, and your effort Mark.👍 ⌚⌚⌚⌚⌚ five watch star's 👏🖖

[@Klockwood1]

I’m a welder and with anything but sapphire I have a problem of if a spark hits the crystal it will actually melt it and leave a little divot where the spark hit it

[@lesgarten]

That Sinn Chronograph was freakin' awesome!

[@hemanthpaularigela4773]

Hi mark. I learned so much from your videos about watches. They are very interesting. Recently I've purchased 350$ divers watch from MVMT. They claimed that the watch have sapphire.ive tested it in a diamond shop and it was showing sapphire. But once I've bumped it on a wall tile and it got scratched. Does sapphire really scratch?

[@paulhiggins4111]

Hi Mark , I just bought a Piaget polo s ...water resistant to 100 meters but does not have a screw crown . I would like to swim in the ocean to a depth of 10 to 20 feet and dive off the back of the boat 🚣‍♀️. Should I be concern that damage will occur? Thx Paul

[@Prussia_is_not_yet_lost.]

First I went cheapo for an Invicta watch with a "Propietary cratchresistant Crystal" which scratched at the first opportunity. The scratches were annoying to me and I tried to buff them out to no avail. I sold this piece of crap. Then I went expensive for an 150$ Wenger Commando quartz watch which I allmost never use but it does whats supposed to do. That Wenger is supposed to be "swiss made" and has an sapphire Crystal. That Crystal has no scratches whatsoever on it. Go sapphire or glass if you really cant afford sapphire. No plastic Crystals whatsoever. Scratches on an watch are to annoying to stare at specially when you pay 80$ for a plastic watch and realise later you could have gotten a sapphire one for 150% - it's worth the lill' extra.

[@Hobby-zn7ce]

Great vid especially the water test info. Are there different levels of hardness with the sapphire crystal?

[@kirkdarling4120]

Your "Look and Learn" videos are so informative and easy to understand. Thank you.

[@joeyalfaro2323]

I come from car background one day I'm watching Eastbay supplier video. Guy has polish with gold dust as abreadive in cream he removed wiper blade scratch. I'm assuming if glass is worth effort.

[@XFS540]

If it could be done, how expensive would it be to replace an acrylic crystal with a sapphire crystal?

[@Vv20vV]

Is it possible to purchase sapphire crystals for a watch that was made with mineral? I own several watches that has mineral crystals, but would like to replace it with sapphire.

[@karategk1]

I own a citizen eco drive with their usual soft mineral crystal that is terribly scratched up. I asked if Citizen service center if I could have them put a sapphire crystal on it, and they said the watch case would not support sapphire. But I'm not paying Citizen $100 to put another crappy mineral crystal. I'd rather buy a hardlex crystal and try putting it on myself.

[@justincourtney8691]

In some cases yes. I put an AR treated sapphire crystal in my seiko SKX.

[@EverynyanSan]

What's the approximate price of this glass for 3.5cm wide and 1mm thick glass? e.g. for an order of 100 pieces

[@lndyrd]

i have tiny scratches on my Islander Great Wave Samurai which is why i came here. I am surprised because it is sapphire (and i don't have any diamonds that could scratch it). Does this mean the AR coating is on the outside and is what got scratched?

[@pedrosaenz2800]

Is it possible to replace plexiglass from vintage Rolex with a sapphire??

[@user-cq5fb7cd2b]

Hi Long Island Watch. I have two watches with a mineral crystal. However when I do the water drop test, the water leaves no trial and resembles the effect a water drop has on a sapphire crystal. How is this possible?

[@mostirreverent]

There are different types of glass. I’m assuming that’s borosilicate (i.e. Pyrex)

[@SmokeRingsPipeDreams]

Which resists shattering more, mineral, or sapphire?

[@islandwatch]

Mineral would be more forgiving in an impact scenario.

[@wargamingrefugee9065]

Hello, Great series, thanks for taking the time to make it for us. Here's a request and a couple of pieces of information. The request first: You said you had your Sinn for ~10 years. How often should a mechanical watch been taken in to be serviced (cleaned and lubricated)? Also, since quartz watches have moving parts, and some even have jeweled bearings, should they be serviced too? And now a couple of factoids: First, the tube, cylinder or dowel shaped thing which sapphire crystals are cut from is called a "boule". Next, if a person is wants to know if their watch has a plastic crystal as opposed to one made of glass or sapphire, there are a couple of fast and fun tests. They can see if their crystal shows finger prints easily. If it does, then it is not plastic. Another test is to place the crystal of their watch on their forehead. If it feels cold, like the metal back of the watch, then the crystal is glass/sapphire. If it feels warm, as opposed to the metal case back, then the crystal is plastic.

[@islandwatch]

Great information. Thank you! I come from the camp that says "if it ain't broke, don't fix it". My Sinn has never been serviced, its the most accurate watch I own. Ditto with quartz. Though quartz watches, like autos, can indeed be overhauled. I know I'm in the minority where this is concerned, but I feel that there's much more that can go wrong by removing 50 parts and then putting them back, then if you didn't do anything in the first place. If it needs service because its not operating correctly, then of course, service it.

[@wargamingrefugee9065]

Thanks Marc.

[@tejasmodiadv]

Long Island Watch thanks

[@robertocastillo2260]

Did you know how to polish the cyclops of a Rolex to eliminate the scratches?, thanks!!!

[@allanredford6070]

great video, Marc. just got a Pulsar, very flat, nearly flush crystal, . Hardlex mineral with incorpoated boron. very clear view, maybe some coating. my watch solar, black textured dial,gold hands,indexes, lumed.. told that gold tone links, dial ring, hands,indexes, all PVD'd is it true saphire more prone to shattering on an impact? why is Pulsar, Seiko's mid-range brand ignored by you guys - experts?- cos all quartz-based? Pulsar designs different to Seiko collections. my 3rd one, all AOK.-accurate,strong, well finished. I, for one would like to see some review-tests on them,

[@kaibaCorpHQ]

If I scratched my sapphire crystal watch out hiking or something, I'd retrace my steps pretty fast after noticing lol.

[@edmund8954]

lmao

[@Lockhart2000]

In order to find the diamond you brushed up against?

[@Younk13]

Great info as always. I would love a video explaining how to use GMT. Recently purchased one and I'm confused lol

[@anthony.catbagan]

I've seen "convex crystal glass". What is that? Mineral or Acrylic?

[@JonathanGrandt]

This was a great video. Very informative. I feel like a nerd.

[@mostirreverent]

You can easily scratch the anti-reflective coating. Also some coating give off a blue hue. I’m not sure what the different types of coatings. Different materials will give a different contact angle which is the amount of spherical nature of the drop, Based on hydrophobicity

[@paulsteele6120]

Well Mark, you being in the watch game will know that the difference in cost per unit is not that great, however the harder the crystal it becomes difficult (in fact, almost impossible) to shape. As with"doming" ,if you want that affect especially on vintage watches you will have to go "plastic". However like many things that go on in the watch trade "all is not clear," excuse the pun! A rough and ready way is like checking diamonds against "paste". The sapphire due to it' crystal lattice construction just like diamonds will feel cool against your cheek as against plastic which always feels err 'uncool' even when it comes straight out of the fridge. Someone, was saying the other day about the hardness testing watch crystal glass using a Vickers hardness tester, don't think I'd like to be around as the diamond point is pushed into the glass surface, it would be spectacular (sorry for that pun as well).

[@buzzufy]

This is a great video, glad to learn the basics of watches. Thank you for the video.

[@pootthatbak2578]

Great, simple advice..just restoring a steeplechase mens watch by concord..i am pleased to report my crystal is sapphire. The cool to the touch, and beading water confirmed it. Thank you so much.

[@vicever08]

I just check reflection and compare it with known mineral glass or sapphire, but only works for crystal without AR coating.

[@That1BVP]

I want to put a sapphire crystal on my vintage swiss army watch. It probably will cost more than the watch itself though. But that doesn't matter, I plan on keeping this watch my whole life.

[@roygardiner2229]

Thank you. I am learning something new with each episode.

[@thomasellis1814]

Wow omg I love this video!, especially the water hack

[@scottsteibel]

I grew up on Long Island, the watch information is interesting, but your Long Island accent so reminds me of home. Be well.

[@GunCollector007]

Thanks. Just ordered some poly watch for a vintage IWC.

[@MFP2241]

I have a Sector plastic case watch which I want to upgrade with mineral or sapphire glass. Is it possible? I don't know about any plastic case/glass combination watches (probably I don't know a lot about watches anyway)...

[@mirakel64]

What is hardlex glas? Ik have a seiko kinetic with hardlex a also have a rado ceramica with saffier, my seiko has diep groves, my rado ceramica doesn;t have any scratch on my class or bracelet

[@genehollon6989]

VERY INTERESTING INFORMATION.I have a Rolex I am having a sapphire crystal installed.

[@abdulhamidketchman8599]

What about flame infused invicta crystals?

[@wizardofahhhs759]

My Citizen watches have Swarovski crystals and my Luminox has sapphire crystal. I've found that the Citizen crystals are pretty much scratch resistant.

[@lindakorthanke4242]

Hello there!!! Thank you so much for your videos, Ive been watching them for almost 2 hours now. You are a kind person for sharing your talents, I been picking up watches at estate sales and want to add it to my many interests how to fix them when I retire from my job next year!!! My question to you or maybe a watch and learn? Some of the watches i purchased have no batteries in them nor have written any where battery size info. What would be the best way to get batteries that would work best?

[@ClassicBMWFanInQuebec]

Great video again! Thank you. What about Hardlex, the crystal used by Seiko? Is it just plastic with a different branding? I have it on my SNK793 and so far it's been surprisingly resistant to scratching.

[@ClassicBMWFanInQuebec]

Wow that's embarrassing, I just saw there's a section about Hardlex in the video...

[@noelle1314]

I've seen many reviews and videos where hardlex scratches fairly easily. Sapphire crystal is almost impossible to scratch but will shatter, hardlex is made to not shatter easily.

[@ohroonoko]

noelle1314 Hardlex does NOT scratch “fairly easily”. It is almost as hard as sapphire and much much harder than mineral glass. I also performed the water drop test on my Grand Seiko (Hardlex) and Omega Seamaster (sapphire) and the drop on the Harldex beaded and ran off better than on the sapphire and just like it did on the sapphire in the video. Hardlex is a pretty great material that only saves money on the watch because it’s easier to manufacture.

[@Koloherides]

you give good watch. will polywatch fix glasses

[@ilyaibragimov6255]

Really thorough. Thank you Marc for this series, really looking forward to what you have in store!

[@adbraham]

There is an easy way to tell sapphire from mineral; based on sapphire, being crystalline in structure, being a much better conductor of heat than glass . . . This is easiest to do when you have a 'control' watch with a known material used for the crystal. You can try this for yourself with two watches; one sapphire, the other mineral: leave both watches on a surface well away from heat (even body heat), for a few moments to equilibrate, then simply pick up on after the other and touch the 'glass' briefly against your lips. The sapphire will feel noticeably colder than the glass. This is only really useful when you have control watches of known material as it relies on the perceived difference between the two materials

[@gregalonzo747]

I would like to about mineral crystals that have a sapphire coating. Is it durable? How long does the coating last? Great series, thanks for sharing your time knowledge.

[@aHigherPower]

Mark what spring bar tool do you recommend for multi-brands ? Do you have a brand name preference? Thanks

[@vladchan]

I used to buff out the plastic crystals with toothpaste.

[@tjwright]

What does "double domed" mean in a crystal?

[@gregalonzo747]

I have a few questions, what about mineral crystals that are sapphire coated? Is it really a plus? How long does the coating last? Can it be reapplied? By the way, I love the Watch and Learn series. You share important information and in an entertaining manner)))

[@louisogorman4806]

When putting crystal in use flat or deep die ?

[@orangewheels01]

Hi mark, I've watched this video a couple of times now, very interesting, is the cyclops saffhire as well as the crystal? Many thanks.

[@jmahaney3]

Marc, can a cyclops window be added to any crystal or just the sapphire?

[@axelfoley1768]

The sapphire glass on my watch reflects light like a crazy man. Ruins my expensive watch.

[@rajgill7576]

Yea you should get a saphire crystal that has an ar coating underneath

[@briancarruthers1738]

Where can I buy domed tonneau crystal?

[@miguelteixeira5438]

The water trick actually works thank you 😊

[@fadih6696]

hi how do I remove antiglare coat from my watch crystal, it has loads of scratches !

[@laurencestemarie]

The good oi diamand war of 2086

[@demej00]

Great information thanks!

[@abhishekbanyal7096]

Excellent Video. I have a Seiko Hardlex front and back on mine. Not as good as Sapphire but remain flawless to this day.

[@chefduane3742]

Marc, I am considering adding a square magnifier to a watch with a day/date complication. I am comfortable with the uv glue process, but what size is standard? I see sizes from 3.5 x 4.3mm all the way up to 5 x 9.5mm. My day/date window is standard size but what is the standard square magnifier size. Any suggestions?

[@islandwatch]

I will admit when I am outside my realm, and this is something I am not familiar with, sorry.

[@parisryan5950]

very helpful tips, thanks!

[@1cookgs]

Great information. I really enjoyed learning about watch crystals.

[@polarroller4848]

Great channel. How about a video on water resistant testing of watches during manufacture. Do they test deeper than they specify on watch cases etc...

[@CodyCannon11]

You said the Plastic (Hesalite) goes on the Junkers and Zeppelin? Is this a good thing? I thought these German watches were fairly high quality...is the Hesalite decent?

[@CodyCannon11]

I am really planning on buying the Quartz Zeppelin Chronograph in the near future. It seemed nearly identical to the mechanical version but essentially 1/4 of the price. Beautiful High Quality German watch from what I understood.

[@tejasmodiadv]

Wow for the water test

[@islandwatch]

Great!

[@c.s.4273]

No sapphire, no watch for me.

[@juanmejia2198]

Can I order a cristal Safire from you to replace the broken one in my watch ? I have a invitation diver Invicta Please let me know. Thank you

[@juanmejia2198]

Replay to my e mail [e-mail] thanks

[@josephj6521]

Cheers! 👍 Hydrophobic, now that’s a great way to describe the sapphire crystal. 😉

[@ohroonoko]

13:32 Seiko Hardlex, good for you to mention it but you don’t give much info about it. If sapphire is a 9 on the hardness scale, Hardlex is a 7. Sapphire is more scratch resistant but also more brittle, whereas Hardlex is more shatterproof. The cost differential is major while the hardness differential is minor and makes Hardlex a more attractive option due to the cost savings.

[@eric_maya]

and with the Sapphlex you can have the best of both worlds!

[@FanoelGutierrez]

should we mention that one glass is domed the other is flat? wouldn't that also alter the way the droplet behave?

[@randallcornelius925]

how do I know what kind of glass my seiko watch has? It's fairly old

[@artl52]

Nicely done! Would like to see more info (video) on the parts of mechanical watch - how the gear train works and what each piece does. Thank you

[@leonardc1303]

The first key to "keeping it interesting" is getting to the point quickly and succinctly and not lingering on a point and repeating and rephrasing the same point over and over again.

[@thearcanearcade4923]

Leonard C perhaps it's intentional :)

[@carlitoxb110]

These watch and learn videos are so valuable for us beginners to the hobby of watch collecting, I appreciate your effort teaching these concepts

[@ronjenkins4257]

My Hardlex crystal on my Seiko is scratched a bit after not long ownership, but my cell phone is still flawless. How about Gorilla Glass on watches?

[@islandwatch]

Good idea!

[@grumpybollox7949]

this makes me wanna buy a new watch every episode

[@coffeeisgood102]

Because plexi glass can be easily repaired I prefer those. I use baking soda and water and use toilet paper to rub it with. The crystal comes out like from the factory. On my Omega Speedmaster which sports a sapphire, it will keep the scratch for the rest of it's life. I wish Omega had used plexi glass on that watch. Great video. Keep them coming.

[@islandwatch]

Thanks! Toilet paper, who would have guessed!?

[@kargi42]

Harold Bullock The Original Moonwatch Speedmaster still has haselite.

[@pericodelospalotes5738]

What did you do??? Sapphire crystal is almost impossible to scratch, did you fall from a motorcycle or any other serious accident? I once suffered exactly that and my Eco-drive Citizen got scratches in its titanium case and bracelet but the sapphire crystal remains perfect. I never wear mechanicals riding my motorcycle because the vibrations could damage the mechanism.

[@pborgia1]

My 1967 pre-moon Speedmaster still has its Hesalite crystal and it is beautifully clear. I have buffed out scratches a few times with Noxon or Flitx metal polish. They work great. Also Omega still uses Hesalite on the Speedmaster moon watch.