Opal Information

The Opal can be called the most mysterious of all gemstones. Every opal is different and individual, one of the most spectacular precious gemstone. Nature has produced a fascinating display of all colours of the spectrum by arranging amorphous silica spheres of similar size in regular layers in an infinite variety of shades, patterns and brilliance, exposed as unique precious opal. Red is rarest and can only be produced when large sphere size is present (we are talking about sizes less than 1/1000mm).

What is Opal?solid Opal QueenslandOpal Pendant Solid Australian Opal

Opal = Si2.nH2O Non- Crystalline form of Hydrated Silica and contains 4% to 9% water.
Hardness: 5.0 -6.5 a mineral of medium hardness
Specific Gravity: Very low 1.9 to 2.3
Occurring as Veins and Nodules (nobbies)

Opal derives its name from the Roman word, "Opalus," meaning 'to see a change (of colour)'. The early Greeks thought opals gave their owners the powers of foresight and prophecy. Romans adored the opal as a token of hope and purity. Eastern people regarded it as sacred and Arabs believed it fell from heaven. Historically, opal has long been associated with royalty. A beautiful opal called 'Orphanus' was set in the crown of the Holy Roman Emperor and was said to guard the regal honour. Opals are also set in the crown jewels of France. Napoleon gave Josephine a beautiful opal with brilliant red flashes called 'The burning of Troy', regarding her to be his 'Helen'. Shakespeare compared the play of colour to shifting inconstancy of the mind.

How should one choose an Opal?

Each opal is very unique which is described as having character and therefore choice is a matter of your personal taste. Explore the full range of shapes, colours and varieties, some of which are seldom seen outside of Australia, and choose the one that appeals to your own personality and style. Opal is birthstone for June & October and presented for the 14th & 18th wedding anniversary. 

Gemstone Healing Guide:  http://www.freespiritemporium.com/guide.html 

Opal helps with stomach and intestine problems, recall of past lives, aids inner beauty, faithfulness and eyesight. The value of Opal is based on the following criteria: brilliance or lustre (brightness of colour), rarity of the colour or spectral colour range, type of pattern, any unique colour pattern, face-up Display (not only showing its beauty from acute angles), character, cut, shape, size, inclusions and imperfections. In these categories opal is priced per carat weight (0.2g). Boulder Opal is occurring in thin veins in sedimentary ironstone boulders found mainly in the arid regions of western Queensland and is unique to Australia. It is naturally bonded to its host rock, dense brown ironstone. Boulder opal may be light, dark or black. By modern designers boulder opals are used cut as well as shaped like its natural features are showing. In the last twenty years this type of opal has become extremely popular as it can display the same darkness and brilliance as a high quality black opal. The Yowah Nut received its name from the place where it is found and from its shape. It is a small boulder containing most diverse kernels of opal patterns and is perhaps the most unusual variety of boulder opal. Cut and polished, they inspire many artists to create extraordinary jewellery. Where the Opal is mixed through the ironstone it is called Matrix Opal. Opal can also be found as a pseudomorph replacing fossil shells, bones, or wood. The bodymass (potch) consists of random sphere sizes in irregular layers, and is opaque, usually white, grey, bluish, brown or black. Precious Opal often forms as a layer on potch. Black Opal has a natural dark or grey Potch base or dark body colour against which the play of colour shows up brilliantly. To find a matching pair can be very difficult. Almost all of the world's supply of Black Opal is Australian, mainly from Lightning Ridge NSW. Quality black opals can fetch prices equivalent to a good diamond on a per carat basis.

Lately dark Opals were found in Mintabie S.A., similar to black opal. Light Opal mainly comes from Coober Pedy, Mintabie and Andamooka in South Australia. The descriptive names "white", "milky", "grey", and "semi-black" Opal refer to the natural potch base or body colour of the Opal.

Crystal Opal is translucent with no opaque potch base and found at all opal fields. Some Crystal Opals show no colour unless put on a black background. These stones, when used for jewellery are usually set enclosed with background e.g. blackened silver or cement. This does not detract from the price. 

Jelly Opal is very transparent.

The back of Opals is not always polished and can have  inclusions. This does not effect the price.

Sometimes a cutter polishes the back to give the option of setting the stone either way.

Opal Nomenclature and Classification

Opal is Australia's National Gemstone. Australia produces 95% of the world's natural precious opal supply. This nomenclature encompasses all types and varieties of opal to provide a standardisation of terminology but does not establish any valuation methodology. The Australian Gemstone Industry Council Inc. in collaboration with the Australian Gem Industry Association Ltd., the Gemmological Association of Australia Ltd., the Lightning Ridge Miners Association Ltd. and the Jewellers Association of Australia Ltd., has produced the following nomenclature for the classification of opal. Opal is a gemstone consisting of hydrated amorphous silica with the chemical formula SiO2.nH2O. There are two basic forms of opal described by visual appearance.

Precious Opal - is opal which exhibits the phenomenon known as play-of-colour, produced by the diffraction of white light through a micro-structure of orderly arrayed silica spheres to produce changing spectral hues.Common Opal and Potch - is opal which does not exhibit a play-of-colour. The distinction between common opal and potch is based on formation and structure. Potch is structurally similar to precious opal but has a disorderly arrangement of silica spheres. Common opal shows some degree of micro crystallinity.

Types of Natural Opal

Natural opal is opal which has not been treated or enhanced in any way other than by cutting and polishing. There are three types of natural opal, with varieties described by the two characteristics of body tone and transparency.   

  • Natural Opal Type 1 - is opal presented in one piece in its natural state apart from cutting or polishing and is  of substantially homogenous chemical composition.   
  • Natural Opal Type 2 - is opal presented in one piece where the opal is naturally attached to the host rock in  which it was formed and the host rock is of a different chemical composition. This opal is commonly known as boulder opal.   
  • Natural Opal Type 3 - is opal presented in one piece where the opal is intimately diffused as infillings of pores or holes or between grains of the host rock in which it was formed. This opal is commonly known as matrix opal.

Varieties of Natural Opal

The variety of natural opal is determined by the two characteristics of body tone and transparency.  

Body Tone

The body tone of an opal is different to the play-of-colour displayed in precious opal. There are three varieties of natural opal based on body tone. Body tone refers to the relative darkness or lightness of the opal when ignoring the play-of-colour. 

Black Opal - is the family of opal which shows a play-of-colour within or on a black body tone by reference to the AGIA Body Tone Chart N1, N2, N3 and N4 when viewed face up. 

Dark Opal - is the family of opal which shows a play-of-colour within or on a dark body tone by reference to the AGIA Body Tone Chart N5, N6 when viewed face up. 

Light Opal - is the family of opal which shows a play-of-colour within or on a light body tone by reference to the AGIA Body Tone chart N7, N8 or N9 when viewed face up. The N9 category is referred to as white opal. 

Opal with a distinct coloured body (such as yellow, orange, red or brown) should be classified as black, dark or light opal by reference to the AGIA Body Tone Chart with a notation stating its colour hue. 


Opal shows all forms of diaphaneity and ranges from transparent to opaque. Natural precious opal which is  transparent to semi-transparent is known as crystal opal. Crystal opal can have either a black, dark or light  body colour tone. The term "crystal" in this context refers to appearance not a crystalline structure.

Opal Treatments

Opal can be subjected to various types of treatment. Present CIBJO guidelines state that any method of treatment other than standard cutting and polishing must be disclosed and the process used specified on all invoices, advertising and commercial documents. Types of treatments include colour enhancement, heating, painting, dying, resins and waxes, oiling or any application of chemicals. Opal is treated to change its natural appearance, structure or durability. Opal is colour enhanced in opal inlay jewellery where usually a thin solid crystal opal has black paint or glue applied or set above black painted jewellery. 

Composite natural opal consists of natural opal laminates, manually cemented or attached to another material. The opal component is natural opal. There are three main forms of composite opal: 

  • Doublet Opals - are a composition of two pieces where a slice of natural opal is cemented to a dark base material.
  • Triplet Opals - are a composition of three pieces where a thin slice of natural opal is cemented to a dark base material and a transparent top layer, usually of quartz or glass.Both doublets and triplets imitate black opals, but are a fraction of the cost.
  • Mosaic and Chip Opals - are a composition of small flat or irregularly shaped pieces of natural opal cemented as a mosaic tile on a dark base material or encompassed in a resin.
  • Synthetic Opal - Synthetic Opal is material which has essentially the same chemical composition and physical structure as natural opal but has been made by laboratory or industrial process. Synthetic composites exist as synthetic doublets, triplets or mosaics and must be disclosed as synthetic composites.
  • Imitation Opal - Imitation Opal is material which imitates the play-of-colour of natural opal, but does not have the same physical and chemical structure or gemmological constants as natural opal.References

Australian Opal and Gem Industry Association PTY LTD

Care for your Opal

  • Protect the stone from hard hits of other Jewellery items or heavy work e.g. bricklaying – store separately. Avoid extreme sudden temperature changes and very low humidity (desert or bank vaults).
  • Never use harsh chemicals, bleach or silver-dipping solutions to clean opal jewellery. Careful with ultrasonic cleaners and steamers! A mild soapy lukewarm water solution and a very soft brush may be used for jewellery set with solid opals, but never immerse doublets or triplets in water as the glue may deteriorate or get soaked, which could make them dull. The safest cleaning method is to use a soft damp cloth followed by a jeweller's polishing cloth for the metal.
  • Finished opals need not be oiled or soaked in water periodically. Some people believe that oil protects the colour. In fact oil hides cracks in a stone, but discolours and dulls the stone over time.
  • If an opal does become scratched and opaque over time, the surface can usually be re-polished by a qualified jeweller or gem cutter.

stunning Opal




Regarding ethical practices in coloured gemstone mining, concerning

  • "Blood" or conflict gems
  • forced or child labour and unsafe conditions
  • destruction of natural habitat or eco-friendly mining

please read Hamid Bros newsletter from one of our suppliers

There were some differences in the referenced lists, so I mention the most common gemstone possibilities I found. There are definitely numerous other beautiful gemstones to explore.


January  Garnetgarnet imageAlmandine garnet imagegarnet kite bead chain image
              Rose Quartzrose quartz imageRose quartz image rectangular facetted  
February   AmethystAmethyst crystal imageAmethyst image marquise cutoval Amethyst image Onyx Onyx Image
March   Aquamarine aquamarin crystal imageAquamarin image Red Jasper Red Jasper imageRed Jasper image rough crystal
            BloodstoneHeliotrope Bloodstone image 
April   Diamondraw diamond imageBrillant imageHeartshaped Diamond imageTrilliant image
           Rock Crystalrock crystal image Zirconblue Zircon image

May   Emeraldemerald imageemerald image Chrysoprasechrysoprase imagechrysoprase image
          green Tourmalinegreen tourmaline imagegreen tourmaline imagetourmalin crystal image

June   OpalsAustralian Opal imagegreen boulder opal imageblue boulder opal image Moonstonemoonstone image
          Pearlsfreshwater pearl imageTahitian Black pearl imageSaltwater pearl imageSaltwater pearl pendant image

July   Rubyruby crystal imageRuby imageRuby imageRuby imageRuby imagepurple Star Ruby image
         Carneliancarnelian imagecarnelian imagecarnelian imagecarneol image

August   PeridotPeridot image Olivin AventurineAventurine imageblue Aventurine image Quartzquartz image

September   SapphireCeylon type blue Sapphire imageoctagonal IndianYellow sapphire imageAustralian green Sapphire imagepink sapphire imageyellow Sapphire image fancy cutpurple Sapphire imageoval faceted Sapphire imagependant sapph multicolouredpendant sapphires multicoloured
                   Lapis LazuliLapislazulil imagelapis lazuli image rectangular beads

October   Tourmalinepink_black_bicoloured_tourmaline_imagenecklace bicoulored Tourmaline imagePendant Yellow Gold rectangular and oval turquoise tourmaline images OpalAustralian Opal imageSolid Australian Boulder Opal image

November   Topazyellow Topaz imageBlue Topaz image round facettedblue Topaz image Tiger's Eyetigereyetiger eye bead image

December   Zirconblue Zircon imageBlue Zircon image round facetted TurquoisTurquoise image rough uncutTurquoise image highly domed cabouchonTurquois Mountain Spiderweb image


Zodiac or Astrological StonesStarsign symbols

Jan20-Feb18       Aquarius     Sapphire, Garnet
Feb19-Mar20       Pisces        Coral, Amethyst
Mar21-Apl19       Aries          Amethyst, Bloodstone
Apl20-May20      Taurus        Emerald, Sapphire
May21-Jun21      Gemini       Aquamarine, Agate
Jun22-Jul22        Cancer       Jade, Emerald
Jul23-Aug23       Leo            Ruby, Onyx
Aug23-Sp22       Virgo          Carnelian
Sep23-Oct23      Libra           Diamond, Chrysoberyl
Oct24-Nov21      Scorpio       Topaz, Beryl
Nov22-Dec21     Sagittarius   Turquoise, Topaz
Dec22-Jan19      Capricorn    Agate, Ruby

Wedding Anniversary List

  1    Clocks
  2    China
  3    Crystal & Glass
  4    Electrical Appliances
  5    Silverware
  6    Wooden Ware
  7    Desk Sets, Pens& Pencil Sets
  8    Linen  & Lace
  9    Leather
10    Diamond Jewellery
11    Fashion Jewellery, Accessories
12    Pearls or coloured stones
13    Textiles & Furs
14    Gold Jewellery, Opal Jewellery
15    Watches
18    Opal Jewellery
20    Platinum
25    Silver Jubilee
30    Diamond
35    Jade
40    Ruby
45    Sapphire
50    Golden Jubilee
55    Emerald
60    Diamond Jubilee
For information on precious gemstones please refer to the International Colored Gemstone Association ICA:  www.gemstone.org
Gemstone Healing Guide:  http://www.freespiritemporium.com/guide.html
In-depth astrology readings.
Daily love horoscope, love compatibility, matches, weekly / monthly forecast readings for zodiac signs.

How to keep your jewellery in good condition

 Jewellery Care:

Rough work like bricklaying, gardening, washing dishes etc. could harm every ring or leave deep scratches.

Pearls should not be worn in saltwater or chlorinated water, but wear them frequently as our skin enhances their lustre. Avoid shampoo, body lotion, hairspray, silver dipping solutions etc. to come in direct contact with pearls.

Silver dipping solutionsare not suitable for any kind of  OPAL or PEARL jewellery. Heat, Water or other liquids can dissolve the glue in between the layers of opal doublets and triplets and make them dull. Opals should not be exposed too long to dampness or extreme dryness.

Get gemstone settingschecked once a year, which we offer free of charge. Necessary repairs come cheaper than replacing a large lost diamond.

How to clean jewellery with CLEAR precious & other fine gemstones

You can heat diamond jewellery in a pot well covered with water, a squirt of a mild dishwashing liquid and cloudy ammonia added to near boiling temperature. But watch out not to forget, as Diamonds boiled dry can end up with a black deposit, which is extremely hard to repolish. To avoid a temperature shock, let it cool down in the water, until you won't burn your fingers any more. Then brush well with a soft toothbrush (no toothpaste because of abrasives in it!) Make sure the plug is in the sink, rinse well with water and dry with a soft lint-free cloth.

A R E  should be taken with emeralds, topaz, opal, lapis lazuli, malachite and gemstones with defects, because they may not withstand higher temperatures than about 60° C. You could always bring jewellery for cleaning or polishing to us or another qualified goldsmith / jeweller.

Wedding Rings

A brief History

It takes 2.5 cubic metres of rock to obtain enough gold to make a wedding ring. The tradition of exchanging wedding rings can be traced back to ancient Egypt. The Egyptians were among the first to use the ring as a symbol of eternal commitment. Later, the early Romans established a custom of exchanging rings when finalising business contracts. Eventually, they included marriage contracts in this practice. Christians adopted the custom during the second or third century, adding inscriptions of love and faith in their wedding bands.

It is not really known when or how the tradition of placing a betrothal or wedding ring on the fourth finger originated. Egyptian legends tell us the ring was placed on the fourth finger of the left hand because the vena amoris (vein of love) runs directly from that finger to the heart. Different countries keep different traditions. In Italy and Australia the wedding ring is worn on the left hand, in Germany on the right hand.

During the Middle Ages at Christian wedding ceremonies, the priest touched the bride's fingers (starting with the thumb) while saying, "In the name of the Father, and of the Son, and of the Holy Ghost, Amen" and placed the ring on her fourth finger. This tradition can still be found today.

An exchange of rings as a love token or betrothal is known in the art of the ancient world already since Antiquity as a symbol of closeness or attachment.

Early wedding portraits are showing a finger ring as the central attribute, usually handed over by the groom to the bride asking her to remain faithful.
During medieval times breach of faith could be punished by beheading with the sword.

Facts about Gold

Gold nuggetJewellery is a very personal expression of your taste and style. It can give pleasure for lifetime and have sentimental value that keeps wonderful memories alive.

Throughout history, precious metals have been highly valued and sought after. Precious metals are extremely durable, because they are highly resistant to attack from the environment. Pure metals are elements and cannot be separated or purified further. In turn, an alloy is a mixture or combination formed by the fusion of two or more metals. Native metals are rarely pure, but are usually found in natural alloys with other metals.

Native gold is generally found as gold dust or mined with other minerals, rarely as nuggets but mostly combined with varying proportions of silver in about 22ct (ct is not the same as gem carat). It is yellow by nature. After refining into fine gold it has 24ct or contains 999 parts pure gold per thousand. Gold has been used in jewellery for over 7000 years. Even today, approximately 80 percent of the world’s output of gold is used in jewellery.

Gold 18ct18ct gold contains 750 parts per thousand (75%) fine gold. For handmade 18ct jewellery  items we alloy the gold ourselves and use for the remaining 250 parts fine silver and fine copper (Palladium for White Gold). The higher the copper content within the 250 parts, the redder the gold will be as in pink or rose gold. 18ct yellow gold is stamped 750 = Hallmark. It is acid resistant and doesn't tarnish. Its melting point lies at 895°C.

9ct gold contains only 375 parts per thousand (38%) fine gold; the rest is a mixture of copper, silver and zinc. 9ct gold is paler and tarnishes easier because of the high copper and zinc content and corrodes after a while (e.g. chains brake easily). To achieve a nice gold colour, it has Gold 9ctto be gold-plated. That is a poisonous, galvanic procedure and harmful to the environment (contains cyanide).

The myth of 9ct gold being harder than 18ct originated from a mix-up of firmness, density, pliability, resistance & malleability (literally meaning “hammer ability”).

“Brinell Hardness” of 18ct: 187 HB, of 9ct: 140 HB is measured by hammering an object into the material and measuring the resistance.

9ct jewellery wears quicker. We only can admire antique jewellery nowadays because it was manufactured in 18ct gold.

In conclusion: 18ct is definitely the best quality. It is also denser and has got a higher specific gravity, therefore is heavier than the same jewellery item in 14ct or lower. If you can afford it, you would not only have the better gold, but also more of it and can pass it on as heirloom. Please note that the prices of precious metals are very volatile and may change at any time.

Palladium or Palladium-based White Gold Alloy recommended for following reasons

Nickel White Gold can tarnish and has to be rhodium-plated to achieve a nice white colour. Rhodium-plating wears off over the years. Because Nickel allergies are on the increase we use a palladium based white gold instead, in the purity of 750 (18ct) & 585 (14ct) parts fine gold per thousand or pure Palladium 950. Palladium is an expensive heavy metal of the platinum group with many advantages including being acid resistant, highly polish-able, very ductile (pliable) and it does not tarnish. There is no need for rhodium plating, therefore no pollution of the environment and no health risk for the manufacturing jeweller. Palladium White Gold is more expensive than identical pieces in Nickel White Gold because it is denser and heavier and more difficult to process as the melting temperatures are substantially higher, at 1480°C. 


Handcrafted Quality-Custom Design

Handmade means: each Jewellery item is individually manufactured to custom designs. Many different techniques are used, e.g.: rolling sheet metal, drawing wires, embossing, filing, hammering, sawing etc. Because of handling, the molecules are pushed very close together which results in a solid material or extended length e.g. A Sterling Silver rod of 8cm straight from the ingot, 5mm thick, weighing 14g  can be rolled through a rolling mill and drawn through a drawplate, resulting in a 215cm long wire of 0.9mm thickness.

We use conflict-free diamonds Russian cut from an Australian Supplier, Australian Opal directly from the miner and only cardboard boxes for packaging (no plastic).


More interesting facts about gold

Already in the 7th century BC in antique Rome gold wire has been used to fasten third teeth. To fill teeth Gold got recommended for the first time in the 16th century.

The first documented gold discovery dates back to 1799 in North Carolina USA. The lump of gold weighed 3.2kg and was used for three years as doorstep until a jeweller recognized the precious piece and bought it for 3.50 dollars.

The Aztecs name for gold was "Teocuitlatl", which means translated: "excrement of the gods"

Australian scientists discovered micro-organisms, which obviously feed on gold. The mining industry is making use of this: The microbes collect traces of gold from the rocks and concentrate them to bigger nuggets.

The Asteroid Eros contains more gold than ever has been mined from the Earth.

20% of the world's jewellery gold has been woven into Indian Saris - a women's garment.

Gold has always been treasured by mankind and therefore recycled for thousands of years. 85% of all the gold ever mined in the world is still in use.

The visor of astronaut's helmets is covered with a thin layer of gold to protect the eyes of the astronauts from sun's radiation.

It is estimated that approximately 10 billion tons of gold is dissolved in the oceans.

Rheumatoid arthritis has been treated for decades with injections of gold solution. Why the metal has an anti-inflammatory effect is still not clear to medical professionals.