Dial materials

Some dials were made last year. Some are as old as the solar system.

Stone, shell, glass and iron from space. Choose a material and the hand finds the age of what the dial is cut from.

Reading the dial

The dial measures time before now. Its numerals run clockwise from one year to 4.6 billion, the age of the solar system, and each is ten times further back than the one before.

Four tracks, from the center out: made, grown, formed, fallen. The name at the top of a track lights up when the chosen material sits on it.
An arc and a dot for each material with an age: the arc spans it, the dot marks its middle. Click or tap one to move the silver hand to it.
A red diamond for each meteorite with a dated fall, on the outer track. Click or tap one to bring out the red hand at its fall.
Two hands. Silver for how old the material is. Red, when a meteorite is chosen, for how long ago it fell to Earth.

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Muonionalusta

Norrbotten, northern Sweden

IVA, fine octahedrite

FormedAbout 4.56 billion years agoFellMore than 800,000 years ago

A minimum, not a date: Buchwald gives a terrestrial age above 800,000 years, after Chang and Wänke. It was found in 1906.

Cuts into large slices, though it needs protecting from corrosion.
230 kg in the Meteoritical Bulletin catalog, a figure that could not be checked here; private recoveries since add more.

Search the catalog for Muonionalusta dials12

The wall, youngest to oldest

Each bezel carries the scale from the dial above, with a pip at the material’s age. Click or tap a dial to set the hand to it.

Osmium

The densest element, crystallized

A few years

MadeMohs 7

The densest element found in nature, grown into crystals from the refined metal.
No two crystal surfaces repeat.
Its 7 on the Mohs scale is the maker’s own figure.

Seen on Czapek & Cie

1 watchSearch

Aventurine

A night sky, poured

Years to decades

Usually made

Most night-sky dials are aventurine glass, filled with tiny metallic crystals. The recipe is credited to Venetian glassmakers.
Natural aventurine is a green quartz that glitters with flakes of mica, 6.5 to 7 on the Mohs scale. The glass has no reliable published figure.
The glitter has its own name: aventurescence.

Seen on Rolex · Christiaan van der Klaauw · Zelos · EREBUS Watches · Van Cleef & Arpels

197 watchesSearch

Mother-of-Pearl

Light, in layers

A few years to decades

GrownMohs 2.5–4

Nacre: plates of aragonite about as thick as a wavelength of light, which is why it shimmers.
Cut from the inner shell of pearl oysters and other mollusks.
By far the most worn natural dial in the catalog.

Seen on Rolex · CHARRIOL · Michel Herbelin · Van Cleef & Arpels · Zelos

1,812 watchesSearch

Abalone

Mother-of-pearl, restless

A few years to decades

GrownMohs 3–4

The inner shell of a sea snail: nacre in blues, greens and violets.
Its color swirls rather than bands, so it changes with every tilt of the wrist.

Seen on Islander

1 watchSearch

Wood

Growth rings, sliced thin

Decades to centuries

Grown

Cut as a veneer and sealed against moisture, so it won’t swell on the wrist.
Burl, a knotted growth on a trunk, gives a figure that never repeats.

Seen on Tense · Luch · Maker's Watch Knot · Xeric · Bell & Ross

24 watchesSearch

Obsidian

Lava that never crystallized

From today back to millions of years

FormedMohs 5–5.5

Volcanic glass: lava that cooled too fast for crystals to form.
Young, as rocks go. Over millions of years it slowly turns to crystal.

Seen on EREBUS Watches · Blancpain · Girard-Perregaux · Beaufort Watches

15 watchesSearch

Coral

A reef, turned to stone

Millions of years, once fossilized

GrownMohs 3–4

The skeleton of a colony of tiny sea animals, built up polyp by polyp.
In fossilized coral that skeleton has slowly been replaced by mineral, so the reef’s structure survives as stone.
The skeleton itself is 3 to 4 on the Mohs scale; where silica has replaced it, agatized coral reaches about 7.

Seen on Formex

1 watchSearch

Opal

Color that moves

Natural: millions of years. Lab-grown: since the 1970s

FormedMohs 5–6.5

Tiny spheres of silica, stacked in rows, break light into flashes of color.
Opal dials can be natural or lab-grown. Both are built from the same stacked spheres.

Seen on Rolex · Arnold & Son · H. Moser & Cie. · Louis Moinet · Schwarz Etienne

94 watchesSearch

Ammolite

A shell turned gem

About 71 to 75 million years

GrownMohs 3.5–4

The fossil shell of ammonites from Alberta, some 70 million years old.
Thin layers of aragonite split light into reds, greens and blues.
Recognized as an organic gemstone in 1981.

Seen on Christiaan van der Klaauw

3 watchesSearch

Agate

Fortifications in quartz

Tens to hundreds of millions of years

FormedMohs 6.5–7

Banded chalcedony that filled holes in old lava, one layer at a time.
Its nested rings are called fortification bands: from above they look like a fortress.

Seen on EREBUS Watches · Zelos · Venezianico · Shanghai Watch · Makoto Watch Company

12 watchesSearch

Tiger’s Eye

Light that slides

About 2.43 to 2.5 billion years

FormedMohs 6.5–7

Parallel fibers inside the quartz throw a band of light that glides as the wrist turns.
The effect is chatoyancy, from the French for the shine of a cat’s eye.
Blue-gray falcon’s eye is the same stone before the iron in its fibers turned gold.

Seen on EREBUS Watches · Pequignet · Michel Herbelin · Baltic · Czapek & Cie

17 watchesSearch

Tiger Iron

Gold, red and steel in layers

About 2.45 to 3.05 billion years

FormedMohs 5–7

Bands of tiger’s eye, red jasper and black hematite in a single stone.
Cut from banded iron formations laid down between about 3.05 and 2.45 billion years ago.

Seen on Rolex · Venezianico

5 watchesSearch

Meteorite

Iron from the asteroid belt

About 4.56 billion years

FallenMohs 4–5.5

Most are iron-nickel from the cores of asteroids, cooled over millions of years.
Etched with acid, the metal shows Widmanstätten lines, a crystal pattern no foundry can grow.

Seen on Rolex · Zelos · EREBUS Watches · Louis Moinet · Ocean Crawler

In search: Muonionalusta 12 · Gibeon 4 · Henbury 1

226 watchesSearch

Meteorites, one by one

Nine iron and stony-iron meteorites from the registry, grouped by what they show on a dial. Each name opens its registry page, and a red diamond marks the four with a dated fall: click or tap its disc to set the dial to it.

Patterned irons

8 meteorites

Iron-nickel that cooled over millions of years inside an asteroid, growing interlocking plates of two alloys. Etched with acid, the plates stand out as crossing bands, the Widmanstätten pattern. How wide the bands grow depends on the metal’s nickel and how slowly it cooled.

Muonionalusta

Norrbotten, northern Sweden

IVA, fine octahedrite

Fell more than 800,000 years ago, a minimum read from its terrestrial age; found in 1906.
Cuts into large slices, though it needs protecting from corrosion.
230 kg in the Meteoritical Bulletin catalog, a figure that could not be checked here; private recoveries since add more.

Still cut for dials. Documented on Formex · Omega · Prim and 5 more.

12 watchesSearch

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Gibeon

Southern Namibia

IVA

Fell in prehistoric times; first reported in 1838.
Its etched pattern is especially suited to a dial cut as one whole slice.
Namibia restricts new removal, so dials are cut from material acquired earlier.

Still cut for dials. Documented on Czapek & Cie · Louis Moinet · Rolex.

4 watchesSearch

Henbury

Northern Territory, Australia

IIIAB

Fell within about the last 5,000 years and made a field of craters; recognized in 1931.
A bright pattern, but large, sound dial blanks are hard to come by.
At least 1.2 tonnes recovered, and its numbered editions have sold out.

No longer cut for dials. Documented on Romain Gauthier · Ludovic Ballouard.

1 watchSearch

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Aletai

Xinjiang, China

IIIE-an

Fall date unknown; found in 1898, with more masses recovered since.
One of the largest known irons, at more than 74 tonnes, with the longest documented strewn field.
Armanty and several other masses are now counted as one fall, under the name Aletai.

Still cut for dials. Documented on Louis Moinet.

Not in the catalogPage

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Toluca

Near Toluca, Mexico

IAB-sLL

Fell probably more than 10,000 years ago; first in print in 1784, with 1776 a later recollection, and known locally before either.
Worked locally as a source of metal before it was ever cataloged.
In Corum’s early meteorite dials, and later in Louis Moinet’s.

Still cut for dials. Documented on Louis Moinet · Corum.

Not in the catalogPage

Cape York

Northwest Greenland

IIIAB

Fell more than 2,000 years ago; known to science from 1818, with its masses located in 1894.
Inuit communities long used it as a source of metal.
58.2 tonnes known; museums hold several enormous named masses.

No longer cut for dials. Documented on Corum.

Not in the catalogPage

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New York

Provenance unknown

IIIAB

Where it fell is unknown; it reportedly came through a fishing-vessel captain in New York.
Its chemistry overlaps the high-iridium end of Cape York’s range.
2.95 kg known by the catalog, a figure that could not be checked here, and the one documented dial, a Louis Moinet, is sold.

No longer cut for dials. Documented on Louis Moinet.

Not in the catalogPage

Canyon Diablo

Meteor Crater, Arizona

IAB-MG, coarse octahedrite

Fell about 50,000 to 56,000 years ago and made the crater; cataloged in 1891.
Among the irons in Corum’s earliest meteorite-dial experiments.
About 30 tonnes recovered.

No longer cut for dials. Documented on Corum.

Not in the catalogPage

Pallasites

1 meteorite

Stone and metal together: crystals of olivine, the mineral that is peridot as a gem, held in nickel-iron. Where an iron shows bands, a pallasite shows its crystals.

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Seymchan

Magadan Oblast, Russia

Main-group pallasite

Fall date unknown; found in June 1967.
Ranges from olivine-rich to nearly all metal, and a metal-rich slice can show an iron’s crossing bands.
323.3 kg is the two masses found in 1967 together; later recoveries are reported beyond them.

Still cut for dials. Documented on AGAT.

Not in the catalogPage

Dated by the mine, not the material

These form wherever the chemistry allows, so one slab can be thousands of years old and the next a billion. Without the mine a slab came from, there is no age to put on the dial.

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Carnelian

Chalcedony with a glow

FormedMohs 6.5–7

Chalcedony colored orange-red by iron oxide. Much of it is heated to deepen the color.
Carved into seals since antiquity, because hot wax won’t stick to it.

Seen on Rolex

52 watchesSearch

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Eisenkiesel

Quartz, stained by iron

FormedMohs 7

Quartz colored by iron: brick-red in some pieces, chocolate-brown in others. The name is German, roughly “iron flint.”
At Mohs 7 it takes a high polish and shrugs off wear.

Seen on Rolex · Formex

75 watchesSearch

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Jasper

A landscape in stone

FormedMohs 6.5–7

An opaque quartz, patterned by iron and whatever else seeped through the rock.
Picture jasper’s bands can read like a range of distant hills.

Seen on Shinola · Chronoswiss · Beaufort Watches

4 watchesSearch

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Chrysoprase

Green from nickel

FormedMohs 6.5–7

Chalcedony colored apple-green by traces of nickel.
The most prized green chalcedony. Much of it is mined in Queensland, Australia.

Seen on H. Moser & Cie. · Piaget

5 watchesSearch

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Malachite

Copper, in rings

FormedMohs 3.5–4

A copper carbonate. Its bands are layers left by copper-rich water.
Soft for a dial stone, at Mohs 3.5 to 4, so it is cut and polished with care.
Ground, it was a painter’s green for thousands of years.

Seen on Piaget · Traska · MARCH LA.B · Formex · Favre Leuba

26 watchesSearch

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Serpentine

Named for a snake’s skin

FormedMohs 2.5–6

A family of green minerals named for their mottled, scaly look.
Soft and easy to carve. Some is sold as “new jade.”

Seen on Piaget · Chronoswiss

2 watchesSearch

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Turquoise

Sky blue, webbed in rock

FormedMohs 5–6

A copper aluminum phosphate. The dark web is the host rock, called matrix.
Porous, so most is stabilized with resin before it can be cut thin.

Seen on Rado · TAG Heuer · Piaget · Blancpain · Van Cleef & Arpels

17 watchesSearch

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Lapis Lazuli

The ultramarine stone

FormedMohs 5–6

A rock, not a mineral: blue lazurite with white calcite and flecks of gold-colored pyrite.
Mined in Badakhshan, Afghanistan, for more than 6,000 years.
Ground, it was ultramarine, once the costliest blue a painter could buy.

Seen on Louis Moinet · H. Moser & Cie. · Traska · Louis Erard · Schwarz Etienne

21 watchesSearch

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Sodalite

Royal blue, veined white

FormedMohs 5.5–6

Named for its sodium. Often taken for lapis, but it rarely carries gold flecks of pyrite.
Some sodalite glows orange under ultraviolet light.

Seen on Piaget

1 watchSearch

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Pietersite

A storm in quartz

FormedMohs 6.5–7

A breccia: fragments cemented in silica after the dolostone around them dissolved, which is why its light swirls instead of running in straight bands.
Found in Namibia in 1962 and named for its finder, Sid Pieters.

Seen on Arnold & Son · Baltic

3 watchesSearch

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Jade

Two stones, one name

FormedMohs 6–7

Two different minerals answer to jade: nephrite and jadeite.
Tough rather than hard. Interlocking crystals make it very hard to break.

Seen on H. Moser & Cie. · Andersen Genève · Memorigin

7 watchesSearch

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Onyx

Black, usually by design

FormedMohs 6.5–7

A banded chalcedony. The deep black of most dials comes from dyeing, a treatment centuries old.
At Mohs 6.5 to 7 it wears well under a crystal.

Seen on Rolex · Van Cleef & Arpels · Girard-Perregaux · Traska · Louis Moinet

61 watchesSearch