Sapphire and acrylic are the two crystals you will meet on Rolex, Patek Philippe and Audemars Piguet watches: synthetic sapphire on everything made since roughly the mid-1980s, and acrylic (Plexiglas, sold by Rolex as its domed "Tropic" crystal and by Omega as Hesalite) on vintage references such as the Submariner 5513, the 1680 and the early Daytonas. Sapphire is almost impossible to scratch but can chip or shatter; acrylic scratches easily but polishes out at home and cracks rather than shattering. Which crystal a watch has tells you its era, changes how it looks in the hand and matters for originality when you buy vintage. This guide explains the difference, when Rolex and the other houses switched, how the Cyclops differs on each, what a replacement means for value, and what to check before buying. Bizak & Co. sources acrylic-crystal vintage references and sapphire-crystal modern ones to order; the used Submariner collection spans both.
Last reviewed on September 22, 2026 by Filip Biczak. Prices are dated observations, not quotes.
Sapphire vs acrylic: the difference in one table
| Acrylic (Plexiglas, Hesalite) | Synthetic sapphire | |
|---|---|---|
| Material | Polymethyl methacrylate, a clear plastic | Aluminium oxide grown as a single crystal, cut and polished |
| Scratch resistance | Low; keys and desk edges mark it | Very high; only diamond and a few ceramics scratch it |
| Impact | Flexes and cracks; rarely shatters | Rigid; can chip at the edge or shatter under a sharp knock |
| Repair | Light scratches polish out with a mild abrasive in minutes | Scratches cannot be polished out in practice; the crystal is replaced |
| Look | Tall dome, warm, distorts at the edge, glows in low light | Flat or slightly domed, clear, can reflect until coated |
| Cyclops | Moulded as part of the crystal | Separate sapphire lens bonded on top |
| Era on Rolex sports models | To the late 1970s and, on the 5513, to 1989 | From 1977 to 1979 on the first models, universal by 1990 |
Mineral glass, the hardened glass on most inexpensive watches, sits between the two and is not used by the four houses discussed here.
What is an acrylic watch crystal?
Acrylic is a clear plastic that watchmakers adopted in the 1930s and 1940s because it could be moulded into a tall dome, sealed against water better than flat glass and did not shatter. Rolex used it on every Oyster until the late 1970s, including the Submariner, GMT-Master, Explorer, Daytona and Datejust, and the domed profile is a large part of the vintage look: the dial sits under a lens that catches light at the edge and softens the printing. Its weakness is the surface. Everyday contact leaves fine scratches within weeks, and a deep gouge will not polish out. The compensation is that light scratches disappear with a minute of rubbing with a fine plastic polish, and a cracked crystal is a straightforward part to replace, though on a Rolex the replacement should be a Rolex Tropic crystal of the right reference so the dome height and Cyclops match. Acrylic also yellows slightly over decades, which some collectors regard as part of the watch's character.
What is a sapphire watch crystal?
Synthetic sapphire is aluminium oxide grown in a furnace, sliced, ground and polished into a crystal. Chemically it is the same as the gemstone without the colour. At 9 on the Mohs scale it resists everything short of diamond, which is why a ten-year-old sapphire-crystal Submariner usually still has a flawless crystal. The trade-off is brittleness: sapphire does not flex, so a sharp knock on a door frame can chip the edge or, rarely, shatter it, and a shattered crystal can shed fragments into the movement. Sapphire is also expensive to shape, which is why most sapphire crystals are flat or only gently domed and why box-shaped sapphires that imitate an acrylic dome cost more. Rolex, Patek Philippe, Audemars Piguet and Richard Mille all fit sapphire across their current ranges; Richard Mille's tonneau cases use sapphire curved in two directions, and the RM 056 and RM 07-02 have entire cases machined from it.
When did Rolex switch from acrylic to sapphire?
| Reference | Crystal | Years |
|---|---|---|
| Submariner 5513 (no date) | Acrylic throughout | 1962 to 1989; replaced by the sapphire 14060 |
| Submariner 1680 (date) | Acrylic with moulded Cyclops | 1969 to 1979; replaced by the sapphire 16800 |
| Submariner 16800 | Sapphire, one of the first Rolex sports models with it | 1979 to 1988 |
| GMT-Master 1675 / 16750 | Acrylic on the 1675; the 16750 kept acrylic through the early 1980s | 1959 to 1988; the sapphire 16700 and 16710 followed |
| Daytona 6263 / 6265 | Acrylic | To 1988; the 16520 of 1988 has sapphire |
| Datejust 1601 / 16014 | Acrylic on the 1601; sapphire on the 16014 from 1977 | The Datejust was among the first Rolex lines to move |
| Explorer 1016 | Acrylic throughout | To 1989; the sapphire 14270 followed |
The change ran from the late 1970s to 1989, line by line. Rolex's first sapphire crystals appeared on quartz and Datejust references in the 1970s and reached the sports models between 1979 and 1989. The current models on the Rolex watches page all use sapphire, and Rolex's care and service page describes the crystal as part of the sealed Oyster case that is checked at service. Patek Philippe and Audemars Piguet made the same move in the same decade; the Royal Oak 5402 of 1972 and Nautilus 3700 of 1976 were both designed with sapphire from the start, which was part of their claim to be modern luxury sports watches.
How the Cyclops differs on acrylic and sapphire
On an acrylic Rolex the Cyclops date magnifier is moulded as part of the crystal, so the lens and the dome are one piece. On a sapphire Rolex the Cyclops is a separate sapphire lens bonded to the flat crystal, and Rolex has applied an anti-reflective coating to the underside of the Cyclops on most models since the mid-2000s. Both magnify the date about two and a half times. The tell for a replaced acrylic crystal is a Cyclops that sits in the wrong place over the date or a dome that is taller or shorter than the reference calls for; the tell for a wrong sapphire is a Cyclops that is off centre, loose or missing its coating on a model that should have it. Rolex service crystals are correct parts, but on a vintage watch collectors still prefer the crystal to be period correct.
Anti-reflective coatings and green sapphire
Sapphire reflects more light than acrylic, so most makers coat it. Patek Philippe and Audemars Piguet coat both faces of their sapphire crystals on current references, which is why a Nautilus or Royal Oak dial reads as though nothing sits above it. Rolex coats only the Cyclops and the underside of some crystals, preferring a coating that cannot be scratched off the outer surface; an outer coating on any brand can wear at the edges and show as a faint rainbow. The exception in the Rolex range was the Milgauss 116400GV of 2007, whose green-tinted sapphire was made in-house and, at the time, was said by Rolex to be so difficult to produce that it was not patented. The Milgauss left the catalogue in 2023, so the green crystal now belongs to the discontinued market. The Patek Philippe collection page and the Audemars Piguet collection page list crystal specifications for current references.
Scratches, chips and what to do about them
- Light scratches on acrylic. A fine plastic polish and a soft cloth remove them in a minute or two. Work in small circles and keep the polish off the case and bezel insert.
- Deep gouges or cracks on acrylic. Replace the crystal; a crack lets moisture in. Use the correct Rolex Tropic or manufacturer part so the dome and Cyclops match.
- Scratches on sapphire. Genuine scratches are rare; most "scratches" are transferred metal or paint that a fingernail or a drop of solvent removes. A true scratch means replacement.
- Chipped sapphire. Stop wearing the watch and have the crystal replaced; a chip at the edge compromises the seal and fragments can reach the dial or movement.
- Cloudy edges or condensation. The gasket, not the crystal, has failed; a pressure test and gasket change is the fix, and on Rolex it is part of any service.
Does a replaced crystal affect value?
On a modern sapphire watch, no: a service crystal is the same part and nobody can tell. On a vintage acrylic watch, a little, and it depends on what was fitted. A correct-reference Rolex Tropic crystal fitted at service is accepted by most buyers and often improves the watch, since the original would have been scratched. A generic aftermarket dome with the wrong height, or a sapphire conversion on a reference that should have acrylic, lowers the value and marks the watch as tampered with. What collectors pay for on a 5513 or 1680 is the dial, the bezel insert and the case, but a wrong crystal is a signal that other parts may be wrong too. Bizak's sourced catalogue listed a pre-owned Submariner 5513 at US$8,369 on 22 September 2026, sourced to order; a sapphire-crystal 126610LN was listed at US$15,400 brand new and US$13,484 pre-owned the same day. Those figures describe what we saw and will move; ask for a dated quote for the specific watch.
Buying a vintage watch: crystal checks
- Correct type for the reference. A 5513, 1680, 1675 or 1016 should have acrylic; a 16800, 16750 late example, 14060 or later should have sapphire. Anything else is a conversion.
- Dome height and Cyclops position. Compare with a known-correct example; a low dome or an off-centre Cyclops is an aftermarket part.
- Edge condition. Look at the crystal edge under the bezel for chips, cracks running from the edge, or a gap where the gasket has shrunk.
- Clarity. Slight yellowing on acrylic is normal; crazing (a web of fine cracks) means replacement.
- Sapphire coating. On a Patek or AP, tilt the watch under a lamp: a faint blue or purple sheen is the coating; patchy rainbow edges mean wear.
- Service history. A receipt that lists a crystal change tells you which part was fitted and when.
- Price against the band. A vintage reference with a sapphire conversion offered at a full-set original price is overpriced.
Our authentication process checks the crystal against the reference, and the vintage Submariner authentication guide covers the dial and insert that sit beneath it.
Quick answers
Is sapphire or acrylic better for a watch crystal?
Sapphire resists scratches almost completely but can chip; acrylic scratches easily but polishes out and rarely shatters. Modern watches use sapphire; vintage references are correct with acrylic.
When did Rolex start using sapphire crystals?
From the late 1970s, line by line: the Datejust 16014 in 1977 and the Submariner 16800 in 1979 were early examples, and the 5513 kept acrylic until 1989.
Can you polish scratches out of a sapphire crystal?
Not in practice. Sapphire is too hard to polish by hand, and most marks on it are transferred material that wipes off; a real scratch means a replacement crystal.
Does a replaced crystal lower a vintage Rolex's value?
A correct Rolex Tropic crystal fitted at service does not lower it much; a generic dome or a sapphire conversion on an acrylic-era reference does.
Why does a Patek Philippe dial look clearer than a Rolex dial?
Patek Philippe and Audemars Piguet coat both sides of their sapphire crystals with anti-reflective treatment, while Rolex coats only the Cyclops and some undersides so the outer surface cannot wear.
Request a sourcing quote for a vintage or modern reference
Tell us the reference, whether you want an acrylic-era or sapphire-era example, condition and set, plus your budget and timing, through our sourcing enquiry form. We confirm the specific watch, photographs, crystal originality and final price before you commit. Catalogue entries: Submariner 5513 with acrylic crystal, Submariner 126610LN with sapphire crystal; browse the used Submariner collection, the pre-owned watches collection, or sell or trade your watch.
Related reading: Submariner 16610LV Kermit guide · Submariner 16613 Bluesy guide · Vintage Submariner authentication · Submariner price guide.
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