HOME
ABOUT US
ABOUT OPAL
STORE
CONTACT



Home / Opals / Boulder Opal / Page 41

Boulder Opal

Showing 361–369 of 818 results

B2314
$660.00
B2315
$660.00
Sale!
B2316
Original price was: $800.00.Current price is: $550.00.
Sale!
B2317
Original price was: $350.00.Current price is: $250.00.
B2318
$300.00
B2320
$250.00
Sale!
B2321
Original price was: $200.00.Current price is: $140.00.
B2322
$200.00
B2323
$200.00

←
1
2
3
…
38
39
40
41
42
43
44
…
89
90
91
→

HOME
ABOUT US
ABOUT OPAL
STORE
CONTACT



© 2024+The Opalcutter in Perpetuity

QUESTIONS

Please contact us at info@opalcutter.com.au with any specific questions you may have about our products. This website shows only a small fraction of our stock. If you cannot see what you want please contact us with your requirements. We hold large quantities of rough opal material and can supply you with a wide range of colours and grades.

HOW IT ALL STARTED

Opalcutter-Mine

'The Opalcutter' has its foundation in 1982 when Piet and Barbara met. Piet was running the local TAFE (a Technical and Further Education institution) teaching courses in adult education and opal cutting and Barbara, a graphic artist by trade, was visiting from Germany. Barbara and Piet fell in love and married quite soon after meeting. They started mining as a ‘hobby’ and by 1984 it turned into full time for both of them. Over the next few years they mined, cut and polished opal and Barbara used her talents as a designer to create their own jewellery range.

They formed 'The Opalcutter' 1990 in order to share their love and passion for this most unique of gemstones with a diverse range of people around the globe. Having their own shop meant they were able to have complete control of their product and how it was processed.

THE MISSION

Barbara and Piet made it their mission to show the beauty and character of opal by presenting it in the best possible light. To that end they cut and polished as many of their own stones as time permitted or contracted the work to a limited range of craftspeople. In order to blend Barbara’s flair for design and Piet’s talent as a cutter they searched for Goldsmiths with whom they could establish a partnership in the production of the individual and distinctive pieces which characterises their jewellery. It is evident from the finished collections that 'The Opalcutter' has a special place in the industry as a source of unique cut stones and items of jewellery (which are found so infrequently in an age of mass production and large workshop items).

In the early days of 'The Opalcutter' Barbara and Piet concentrated on the ‘Light Opal’ sourced either from their own mines at Coober Pedy or other workings from there as well as Andamooka and ’Dark Opal’ from Mintabie. As part of their work with the stone they frequently searched Australia wide to source ‘Black Opal’ from Lightning Ridge and the Queensland ‘Boulder Opal’ fields to add to their local material.

Opalcutter-in-store

More recently the special properties of the ‘Boulder Opal’ have formed the main part of 'The Opalcutter's offerings. Over the last few years Barbara has made ‘Boulder Opal’ the feature stone of most of her jewellery designs.

After Piet’s untimely death in August 2006 Barbara ran the business almost entirely by herself and continued the dream which had formed the basis of their philosophy and which provided the driving force to keep up the demanding workload.

‘The Opalcutter' closed its doors in Coober Pedy in December 2007.

THE OPALCUTTER TODAY

Barb-and-Edi-2100px

A HAPPY STORY

Barbara married Edi Heide in December of that year and both were working the business together from near Cairns in Queensland. ‘The Opalcutter’ continue to offer high quality stones and individual jewellery items to the public and wholesale over the internet. Since 2012 The Opalcutter shop is located in Montville, in the Sunshine Coast Hinterland.

Barbara and Edi were mining for ‘Boulder Opal’ at Koroit in Queensland and are maintaining their connection with opal miners, cutters and goldsmiths to ensure that they are able to continue supplying high quality, individual pieces of opal and jewellery.

piet-lamont-cutting-opal-2

CUTTING OPAL

So we’ve found some beautiful opal. Now to cut and polish one of nature’s gems.

Firstly we remove any sandstone from the rough opal using a 220 grit diamond wheel and the word is – keep cool – make sure the opal is not overheated – use plenty of water as the coolant.

Next we rough shape the piece and glue the stone onto a wooden “dop” stick. With the stone dopped, grinding is done on the 220 wheel until the exact shape you have in mind is achieved. Turning the stone 360º reveals good symmetry all round. The stone is now worked on a series of diamond impregnated “Nova” wheels – first 360, second 400, third 600, fourth 1200 all the time ensuring lots of water is fed onto the stone to keep heat to a minimum and to carry away grinding debris.

Sequence 01.00_02_34_20.Still001

Wow, look at the beautiful stone now – it’s nearly finished. A quick 3000 polishing wheel and if you are really serious about a mirror finish, I complete polishing on a felt pad impregnated with a high quality cerium oxide and water mixture.

Take the stone off and re-dop (reverse the stone) to finish the backside. All I do is flatten the back using a 220 flat lap and then finally put a setting edge on the stone.

Ah, perfection – a gem from nature with a little help from its friends.

PIET LAMONT'S OPAL STORY

People often ask me – just what’s involved in becoming an opal miner and what do you do?

To begin with, opal mining can be likened to a very expensive hobby, there are no guarantees of making a fortune and you just can’t rely on it for a regular income. This aside, it’s a great lifestyle – freedom to do your own thing and no “boss”. You do as much or as little as you like. There’s only one small problem. Opal is not easy to find!

Prospecting, running expenses and living cost a great deal and on top of this, you may not find opal for months or even years! Why do it then, you ask? Let’s say it’s a bit like gold fever, once you’ve get the “opal bug”, you are hooked. The search for “The Queen of Gems” is like trying to find “The Holy Grail”. Where is that underground rainbow of nature? And when you find it, no two opals are alike and no other stone shows such an array of colours. To see opal glistening in the face of your mine is an unforgettable experience. Every miner is lured by the hope that one day they will find this “rainbow” – it will be their turn, they hope.

waste-dirt-being-removed-by-blowers--large-vaccumn-cleaners-mounted-on-trucks

Now to a brief insight into opal mining. Depending on how deep opal is found will dictate what type of machinery is to be used. Most opal in Coober Pedy is found approximately 3 meters to 30 meters below the surface in what are called “levels” (much like a seam of coal). Shallow levels are mined by bulldozers and excavators. Deeper ground is worked by tunnelling machines – small coal mining type machines.

Once a particular area has been prospected by a miner and the ground is deemed to have “prospects” the miner pegs a claim 50m x 100m then shafts will be sunk to try and locate the traces of opal. The miner goes down these shafts to “read the ground”. If the indicators are good, mining commences. Deep ground mining is done by driving out from the shafts sunk following the seam or level looking for that “pocket” of gem colour using a tunnelling machine. This has a revolving cutting head that cuts away the sandstone. The machine is hydraulic/electric and is the size of a small ‘bob-cat’.

power-winch-to-get-into-the-shafts

The waste dirt tunnelled is sucked up pipes by powerful suction machines called “blowers” and dumped on the surface. So, you keep following a thin layer of “trace” within the level hoping the next gouge will uncover your “fortune”. Along the way opalised fossils such as shells and belemnites can be found. They tend to occur randomly so are often missed. When finding opal I know a percentage will have been missed so all the waste dirt on the surface is processed by machinery called “Noodling ” Machines. This dirt is passed on a belt through a darkened room where ultra violet light fluoresces any opal white. This is handpicked from the moving belt and hopefully, very little is lost.

This opal mining is easy, hey?

A final few words – 90% of all opal found has no value – we call this “potch” and furthermore, 90% of all the work we do is for “nix, nought and nothing”. Crazy hey? Ah, but what a lifestyle!

So, if you ever come to Coober Pedy, look us up at The Opalcutter, experience at first hand our underground living and outback hospitality.

Dreaming of opal....
Piet Lamont
The Opalcutter

Post Script: Piet passed away on 2 August 2006. Since then ‘The Opalcutter’ has moved to Montville in Queensland.

AUTHENTICITY

All items sold by us come with a complete description of the nature / type of opal its size / weight and shape. As well as that jewellery items have a precious metal statement. Items containing precious metals are hallmarked.

AUTHENTICITY OF OPAL

The Opalcutter does NOT sell manufactured or synthetic opal. Unless otherwise stated our opals are solids. Opals described as ‘Doublets’ or ‘Triplets’ are thin slices of real opal supported by a backing, of potch (i.e. low grade non coloured opal material) or ironstone and may be protected / enhanced by a covering of clear quartz. Andamooka opal occasionally is sold as ‘Matrix’. In ‘Matrix’ opal a chemical treatment has been used to increase the black background of the material making the colours appear more intense. Any items containing ‘Matrix’ opal are clearly indicated on our website. Wherever possible we will identify the major region from which a particular opal is sourced and if possible give the field from which the opal came. NB: this is easier to do for opal mined near Coober Pedy as there are a number of quite distinct mining locations around CP. For more information about opal types in languages other than English see:https://www.opal.asn.au/

SUPPORTING ARTISANS

We love to support artisans, local & worldwide. Jewellery and art choices are worn, displayed & given with love so the stories behind the artworks are really important to share with you. It gives another layer of meaning to your special piece.

Regine-Maeckle-optimized

OUR GOLDSMITH - Regine Maeckle

Let us introduce you to our Master Goldsmith Regine Maeckle- the person or ‘face’ behind our impressive handmade jewellery. Regine came to ‘The Opalcutter’ in Coober Pedy in 2001 originally from Germany, close to the Gold and Jewellery city of Pforzheim. Opal was a very impressive new gemstone for her to work with then, and you can see it’s her favourite now!

From classic designs to ‘one off’ Masterpieces, Regine's work is giving Australia’s national gemstone the perfect look! Now permanent resident in Australia and still working in Coober Pedy we count ourselves fortunate to be working together with her.

Regine’s excellent and extraordinary handmade jewellery pieces can be found all over the world.

EDI'S-DIAMOND-EYE

EDI'S LOVE OF GEMS

Edi Heide has a Diploma in Gemology and is a Fellow of the Gemological Association of Australia. He also has completed a Diploma in Diamond Technology. "This is so we can understand what we are getting when we buy precious gems to enhance our opal setting and our customers can be given information on what they are buying". The laws says "If I know I have to tell you. If employees don't know about gems, they are not required, by law, to tell the customer how the stones are treated, the quality, how they are formed and where they come from" says Edi.

It is comforting to know when you buy from The Opalcutter you can be sure you are talking to an expert when purchasing gems and diamonds.

I came in with my partner on a whim as I walked by. What a delight. We spent an hour in this store. So many varieties of opal. We walked out with a beautiful doublet ring. Very reasonably priced for the quality. Next time I visit I'll come back for the matching necklace. Thanks Barb!

Belinda Smythe

Barb and Edi were so friendly and helpful, answering all my questions about the different types of opals, going to so much trouble to help me find just the right pair of earrings. I can't recommend this store enough.

Paula Jayne

My visit to The Opalcutter in Montville was such an eye opener. The opals are stunning, with such an inspiring selection it was hard to choose just one, so I bought earrings and a ring. Barbara and Edi were so welcoming and helpful. I'll certainly be back.

Gracie Knowles

WHAT IS OPAL?

Opal is hydrated form of silica similar to quartz containing a proportion of water (2 – 10%). Its chemical formula is SiO2.nH2O and has a hardness of 5.5-6.5 on the Moh’s scale.

Only 5% of all opal found displays “colour”. Opal with colour has spheres of silica stacked in a regular lattice formation. Light is diffracted from these molecules – small molecules display blue green colours, larger ones , the rarer orange and red colours. The remaining 95% of opal has no value and is called “potch” – opal without plays of colour.

OPAL VALUATION – THE MAIN FACTORS ARE:

BACKGROUND COLOUR AND TYPE

Black - ranging from very dark grey to black
Semi-Black - from dark grey to very dark grey
Grey - ranging from pale grey to dark grey
White (or milky) - opal is opaque
Crystal - transparent light opal
Boulder - opal formed in brown ironstone boulder, cut so the host rock remains on the back
Boulder Matrix - a mixture of opal and the host ironstone
Matrix - from Andamooka, opal and porous rock, after cutting, treated in sugar and sulphuric acid (to enhance the colour)
Fossils - (or pseudomorphs) opal forms in the casts of the original fossil
Opal Doublet - a thin slice of opal glued on a dark backing
Opal Inlay- a slice of opal darkened from behind and glued into the setting.
Opal Triplet - a very thin slice of opal glued between a dark backing and a clear quartz top

DOMINANT COLOUR PLAY

Red has the highest value ranging through to orange, gold, green and blue having the lowest value.

PATTERN

Large areas of colour and flashes have the most value ranging down to “pinfire” (small areas of colour) and “sheen “ patterns are least valuable. “Harlequin” with its checker-board pattern is the rarest.

BRIGHTNESS

The brighter and stronger the colour, the more value an opal has. Cut in a domed or cabochon shape has a higher value than a flat and very thin (< 3mm) cut stone. Weight: All solid opal is sold by weight. 1 carat weighs 0.2 grams (5 carats per gram)

BUYING AND CHOOSING AN OPAL WITH CONFIDENCE

When purchasing your opal ensure it exhibits full colour, is bright, holds its colour when rotated 360° (in varying light conditions) and presents an interesting pattern.

Look for trusted AOGIA members whose reputation and integrity will ensure your opal is exactly as stated in the written guarantee provided with your purchase.

Product knowledge and professionalism of the sales consultant.

HOW TO CARE FOR YOUR OPAL

A solid opal is not affected by water; just occasionally clean with a soft cloth immersed in alcohol to remove the dirt and grease. Doublets and triplets should never be put in water and remember, all opals should not be worn when doing the housework or gardening. Treat your beautiful and rare opal with lots of love. Care for it as any other piece of valuable jewellery.

FRANÇAIS

DEUTSCH

ITALIANO

QU'EST - CE QU'UNE OPALE?

L'opale est une forme hydrates de silice comme Ie quartz avec un pourcentage de 2 à 10% d'eau. Sa formule chimique est Si02.nH20 et elle a une dureté de 5,5 à 6,5 sur l’échelle de Moh.

On ne trouve que 5% d'opales de couleur. L'opale de couleur est constituée de sphères de silice empilées selon un réseau de molécules en treillis régulier. La lumière est difractée à partir de ces molécules - les petites molécules renvoient une couleur bleu-vert, les plus grandes molécules renvoient les couleurs les plus rares, orange et rouge. On appelle « potch » les 95% d'opales restantes qui sont sans valeur et sans jeu de couleurs.

LA VALEUR DE L'OPALE - LES PRINCIPAUX FACTEURS SONT:

LA COULEUR DE LA BASE DE LA PIERRE ET IE TYPE DE PIERRE

Noir - du gris très foncé au noir
Semi-Noir - du gris foncé au gris très foncé
Gris - du gris pale au gris foncé
Blanc -(ou laiteuse) I’opale est opaque
Cristal - opale claire, transparente
Boulder - opale formée dans un bloc de minerai de fer de couleur marron et taillée en conservant Ie bloc de fond
Boulder Matrix - un mélange d'opale et de minerai de fer contenant
Matrix - I’opale en provenance d'Andamooka, I’opale et la pierre poreuse subissent un traitement au sucre et à I’acide sulfurique après la taille (pour rehausser la couleur)
Fossiles - (ou pseudo morphes) I’ opale prend la forme du fossile d'origine.
Le Doublet - une tranche d'opale mince collée sur un fond fonce
Le Triplet - une tranche d'opale tres mince collee entre un fond fonce et un dessus de quartz clair

LE JEU DES COUTEURS DOMINANTES

Le rouge a Ie plus de valeur puis l'orangé, Ie vert et Ie bleu qui a Ie moins de valeur.

LE DESSIN

Plus une opale a de grandes surfaces de couleur et d'éclats, plus elle a de la valeur, viennent ensuite les opales « pinfire » (petites surtaces de couleur) et les « sheen » (reflets). « Harlequin »" , dessin en damier , est Ie plus rare.

LA BRILLIANCE

Plus une opale brille, plus elle a de couleurs dominantes et plus elle a de la valeur.

LA TAILLE

Une forme en dome ou cabochon a plus de valeur qu'une forme plate et tres mince (< 3mm d'epaisseur)

LE POIDS

Toutes les « solid opals » ( non collees) sont vendues au po ids. 1 carat pese O,2gr (5 carats par .gramme)

COMMENT CHOISIR ET ACHETER UNE OPALE EN TOUTTE CONFIANCE

Comme iI n'existe pas 2 opales semblables,c'est difficile, rnais assurez¬vous que votre opale a des couleurs bien franches, brille, conserve ses couleurs si vous la faites tourner a 360' (sous des lumières différentes).

Acheter votre opale chez un des membres agrées par I'A.O.G.I.A dont la réputation et l'ntéqrite sera pour vous I'assurance que votre opale correspond aux criteres mentionnés sur la garantie.

Optez pour la connaissance et Ie professionnalisme d'un vendeur-conseil.

COMMENT PRENDRE SOIN DE VOTRE OPALE

L'eau n'abime pas une « solid opal » (opale non collée ) ; nettoyez -Ia de temps en temps a I'alcool avec un chiffon doux pour oter la saleté et les rnatières grasses. Ne mettez jamais vos Doublets et Triplets dans I'eau et ne portez jamais vos opales pour faire Ie ménage ou Ie jardinage. Soignez et aimez vos opales qui sont belles et rares tout comme tout autre bijou de valeur

ENGLISH

DEUTSCH

ITALIANO

WAS IST OPAL?

Opal ist gewoehnliche Kieselerde mit 2 – 10% Wasseranteil. Die chemische Formel ist Si02.nH20 und hat eine Haerte von 5.5-6.5 auf der Moh’s Skala.

Nur 5% des gefundenen Opals hat Farbe. Gleichgrosse Kieselgel- kuegelchen liegen dicht zusammen und durch Lichtbrechung entstehen die Farben – wobei die kleineren blaugruen und groesseren orangerot zeigen. Die restlichen 95% sind “Potch”, keine Farbe und daher wertlos.

OPAL BEWERTUNG – DIE HAUPTFAKTOREN:

GRUNDFARBEN UND TYP

Schwarzopal - von grauschwarz bis schwarz
Dunkler Opal - mittel – bis dunkelgrau
Grauer Opal - hell – bis mittelgrau
Heller Opal (oder milchig) - heller undurchsichtiger Opal
Kristallopal - heller transparenter Opal
Boulder - Opalformation in braunem eisenhaltigen Gestein, das Muttergestein bleibt mit dem Opal verbunden
Boulder Matrix - feine Risse gefuellt mit Opal in eisenhaltigen Gestein
Opalmatrix - von Andamooka, Opal und poroeser Stein behandelt mit Zucker und Schwefelsaeure (Hervorhebung der Farben)
Fossilien - (Pseudomorphs) praeziser Opal Abdruck des frueheren Pflanzen-oder Lebewesens
Dublette - duenne Scheibe Opal auf dunklem Untergrund geklebt
Triplette - sehr duenne Schicht Opal zwischen dunklem Untergrund und Quartzkappe

FARBSPIEL

rot hat den hoechsten Wert, gefolgt von orange, gold, gruen und blau ist am niedrigsten

MUSTER

Grosse Farbflaechen und “flashes” (Farbblitze) wertvoller wie “pinfire” (Nadelfeuer). “Harlekin” –Schachbrettmuster ist am seltensten

KLARHEIT

Je kraeftiger und leuchtend die Farbe umso hoeher der Wert

SCHLEIFFORM

Hoch und oval ist wertvoller als flach und sehr duenn

GEWICHT

1 Karat wiegt 0.2 Gramm (5 Karat pro Gramm)

OPALKAUF IST VERTRAUENSSACHE

keine zwei Opale sind gleich, aber sie sollten volle Farbe zeigen und halten wenn um 360° gedreht (in verschiedenen Lichtsituationen), und ein interessantes Muster praesentieren

schriftliche Beschreibung und Garantie fuer den Einkauf –Mitglieder der AOGIA (Australian Opal & Gem Industry Association) haben hohe Integritaet und Ansehen

Produkt – und Fachwissen des Verkaeufers

BEHANDLUNG DES OPALS

Massiver Opal ist wasserunempfindlich. Gelegentlich mit einem alkoholgetraenkten weichen Tuch Fett und Schmier abwischen. Dubletten und Tripletten nicht nass werden lassen und Opale nicht bei der Haus – und Gartenarbeit tragen. Behandeln Sie die einmaligen und seltenen Opale mit viel Sorgfalt - wie jedes andere wertvolle Schmuckstueck.

FRANÇAIS

ENGLISH

ITALIANO

CHE COS'È L'OPALE?

L'opale è una forma idratata di silice simile ad un quarzo contenente una percentuale di acqua (2-10%). La sua formula chimica è SiO2.nH2O ed ha una durezza di 5,5-6,5 nella scala Moh.

Soltanto il 5% di tutti gli opali estratti mostra "colori". L'opale colorato è formato da sfere di silice disposte in un reticolato regolare. La luce viene diffratta da queste molecole - le molecole piccole assumono i colori blu o verde, le più grandi, i colori più rari di arancio e rosso. Il rimanente 95% degli opali non ha alcun valore e viene chiamato "potch" - opale senza giochi di colori.

VALUTAZIONE DELL'OPALE - I PRINCIPALI FATTORI SONO:

COLORE BASE E TIPO

Black - Nero dal grigio molto scuro al nero
Semi Black - Quasi –Nero dal grigio scuro al grigio molto scuro
Grey - Grigio dal grigio pallido al grigio scuro
White - Bianco (o latteo) opale opaco
Crystal - Cristallino opale chiaro e trasparente
Boulder - Roccioso, opale che si è formato nei massi di roccia ferrosa tagliato in modo che la roccia che lo ospita faccia da base
Boulder Matrix - Roccioso Matrix un misto di opale e roccia ferrosa
Matrix - proveniente da Andamooka, l'opale e la roccia porosa, dopo il taglio vengono trattati con una soluzione di zucchero e acido solforico (per vivacizzarne il colore)
Fossils - Fossile (o pseudomorfo) opale che conserva la forma del fossile originale
Opal Doublet - Opale Doppio strato un sottile strato di opale incollato su una base scura
Opal Triplet - Opale Triplo strato uno strato molto sottile di opale incollato in mezzo a una base scura sotto e un quarzo limpido sopra.

GIOCO DI COLORE DOMINANTE

Il rosso ha maggior valore seguito da arancio, oro, verde e blu, che ha il minor valore.

MOTIVO

Aree estese di colore e brillantezza hanno maggior valore. Si parte dai motivi "pinfire" (con piccole punte di colore) e "sheen" che sono di minor valore, fino allo "Harlequin" con il suo motivo a scacchiera che è il più raro.

LUMINOSITÀ

Quanto più è luminoso e più accentuato il colore, più alto è il valore dell'opale.

TAGLIO

Una forma a cupola o a “cabochon” ha maggior valore di una piatta e molto sottile (< 3mm di pietra tagliata).

PESO

Tutti gli opali solidi vengono venduti a peso. 1 carato pesa 0,2 grammi (5 carati in un grammo)

ACQUISTARE E SCEGLIERE UN OPALE CON FIDUCIA

difficile scegliere dal momento che non esistono due opali simili. Assicuratevo che il vostro opale abbia colore pieno, luminosità, che mantenga il colore se fatto ruotare a 360° (variazione di luce) e presenti un motivo interessante.

Cercate membri JAA (Associazione delle Industrie di Gioielliere Australiane), le cui affidabilità, reputazione e integrità vi assicureranno che il vostro opale corrisponda esattamente a ciò che è scritto nella garanzia che vi eiene rilasciata con l'acquisto.

Farsi consigliare da esperti del prodotto e professionisti di vendita.

COME AVERE CURA DEL VOSTRO OPALE

Un opale soldo non viene danneggiato dall'acqua; pulirlo solo occasionalmente con un panno morbido inumidito in alcohol per rimuovre sporco e grasso.

Gli opali a doppio e triplo strato non debbono mai essere messi in acqua, e ricordate che gli opali non dovrebbero essere indossati mentre si fanno le faccende di casa o durante il giardinaggio. Trattate il vostro bello e raro opale con molto amore. Abbiatene cura come ogni altro pezzo di gioielleria pregiata.

FRANÇAIS

ENGLISH

DEUTSCH

CONTACT

Name

Email Address

Message

Street Address Shop 4 'The Pottery' 171-183 Main Street Montville QLD 4560 Australia
Postal Address PO Box 84 Montville QLD 4560 Australia
Phone +61 07 54429598 or +61 413809625

OPENING HOURS - temporarily closed until Thursday 11 September 2025

Thursday to Monday 10 am to 4.30 pm

LOCATION & ADDRESS

Street Address Shop 4 'The Pottery' 171-183 Main Street Montville QLD 4560 Australia
Postal Address PO Box 84 Montville QLD 4560 Australia
Phone +61 07 54429598 or +61 413809625

Ring Sizes

Circumference mm	Diameter mm	UK/Aust	US	Japan	Europe
37.6	11.97	A	1/2
38.8	12.36	B
38.8	12.37		1
40.0	12.75	C
40.1	12.78		1 1/2
40.8	13.00			1
40.9	13.04				1
41.3	13.14	D
41.5	13.21		2
41.9	13.33			2
41.9	13.35				2
42.5	13.53	E
42.7	13.61		2 1/2
42.9	13.67			3	3
43.7	13.92	F
44.0	14.00			4	4
44.1	14.05		3
44.9	14.31	G
45.0	14.33			5	5
45.4	14.45		3 1/2
46.0	14.65			6	6
46.2	14.70	H
46.7	14.86		4
46.9	14.95				7
47.1	15.00			7
47.4	15.09	I
47.9	15.27		4 1/2		8
48.1	15.33			8
48.6	15.48	J
49.0	15.59				9
49.2	15.66			9
49.3	15.70		5
49.8	15.87	K
49.9	15.90				10
50.2	16.00			10
50.6	16.10		5 1/2
51.0	16.24	L			11
51.3	16.33			11
51.9	16.53		6		12
52.3	16.66	M		12
53.0	16.87		6 1/2		13
53.4	17.00	N		13
53.9	17.17				14
54.4	17.33		7	14
54.8	17.45	O
55.0	17.50				15
55.5	17.66			15
55.7	17.75		7 1/2
56.0	17.83	P			16
56.5	18.00			16
56.9	18.13				17
57.1	18.19		8
57.4	18.27	Q
57.6	18.33			17
57.9	18.45				18
58.4	18.59		8 1/2
58.6	18.66	R		18
59.0	18.78				19
59.7	19.00		9	19
59.9	19.09	S			20
60.7	19.33			20
60.9	19.41		9 1/2		21
61.2	19.50	T
61.7	19.66			21
62.0	19.73				22
62.3	19.84		10
62.5	19.91	U
62.8	20.00			22
63.0	20.06				23
63.6	20.24		10 1/2
63.8	20.33	V		23
64.0	20.37				24
64.9	20.66		11	24
65.0	20.69				25
65.9	21.00		11 1/2	25	26
65.1	20.73	W
66.4	21.14	X
67.0	21.33			26	27
67.5	21.49		12
67.7	21.55	Y
68.0	21.66			27	28
68.7	21.89		12 1/2
69.0	21.96	Z		28	29
69.9	22.26				30
70.1	22.33	Z + 1	13	29
71.0	22.60				31
71.2	22.69	Z + 2		30
72.0	22.92				32
72.4	23.06	Z + 3		31
73.0	23.24				33
73.7	23.47	Z + 4
73.9	23.55				34
75.0	23.87	Z + 5			35
76.2	24.27	Z + 6