Marcus Tempus
A streak of colour captured in stone.
At the centre of Wildfire is a remarkable 2.15ct Australian Boulder Opal, alive with flashes of electric green, vivid blue, fiery red and orange emerging from its naturally dark ironstone matrix. Its long, organic form has been shaped around the opal itself rather than forcing the stone into a conventional cut — preserving the character that makes Boulder Opal so fascinating.
A fine halo of brilliant-cut diamonds traces the outline, bringing a crisp flash of light around the darker opal, while warm 9ct yellow gold intensifies its extraordinary spectrum of colour.
The result is bold without being overly formal: a little piece of the Australian landscape, millions of years in the making, transformed into something entirely individual.
No two Boulder Opals are ever quite alike. This one is Wildfire.
Details: Natural Australian Boulder Opal · 2.15ct · Brilliant-cut diamond surround · 9ct yellow gold · Fine gold chain · Individual one-off gemstone
The House of Gemstones
Opal can appear to hold colour rather than simply possess it. In precious opal, flashes of green, blue, yellow, orange, red and violet can move across the gemstone as the stone, light or viewer moves.
No two opals present their colour in quite the same way. Body colour, transparency, pattern, brightness and the distribution of play-of-colour all contribute to an individual stone’s character.
Colour Born from Structure
Precious opal’s play-of-colour is produced by the interaction of light with an ordered microscopic structure of silica spheres. Common opal lacks this spectral play-of-colour.Opal is softer and more sensitive than sapphire or diamond. Clean gently with lukewarm water, mild soap and a soft damp cloth. Protect it from hard knocks, abrasion and extreme changes in temperature.
One Gem, Remarkably Different Personalities
White opal has a pale to milky body colour that can provide a soft backdrop for flashes of spectral colour.
Black opal has a dark body tone that can make play-of-colour appear especially vivid and dramatic. Fine black opal is among the most celebrated forms of precious opal.
Boulder opal forms in seams or cavities within ironstone. The natural host rock is intentionally retained as part of the finished gem, creating striking contrast and highly individual patterns.
Fire opal is defined by warm yellow, orange to red body colour. Some examples show play-of-colour, while others are valued primarily for their vivid body colour and may be transparent enough to facet.
Crystal opal is transparent to semi-transparent precious opal, allowing play-of-colour to appear suspended within the body of the gemstone.
In matrix opal, precious opal occurs through the pores or spaces of its host rock, creating a patterned appearance in which colour and matrix become part of one material.
Understanding Natural & Assembled Opal
Opal jewellery can contain a solid natural opal or an assembled stone. Treatments may also be used to alter appearance, so construction and disclosure are important when assessing an opal.
A solid opal is cut from a single piece of opal material rather than being assembled from separate layers.
A doublet combines a thin opal layer with a backing. A triplet also adds a transparent protective cap. These are assembled products and should be described as such.
Smoke, sugar/acid, dye, impregnation and other treatments may be encountered in some opals. Known treatment should be disclosed.
A Gemstone That Performs
Spectral colours can appear, disappear and move as the viewing angle changes, giving precious opal its unmistakable visual character.
The underlying body colour ranges from light to very dark and strongly influences the overall appearance and contrast of play-of-colour.
Colour may appear as pinfire, broad flashes, rolling patches, mosaic-like areas and many other natural arrangements.
The strength and liveliness of the colour display are central to the beauty of precious opal and can vary dramatically between stones.
Marcus Tempus Gemstone Selection
At Marcus Tempus, we select opal for personality rather than chasing a single formula. In precious opal, we consider brightness, pattern, colour range, body tone, transparency, stability and how beautifully the colour responds to movement. In fire opal, body colour and transparency may become the principal attraction.
Marcus Tempus Bespoke
Opal is wonderfully suited to one-of-a-kind jewellery because the gemstone itself can lead the design. Depending on availability, we can source around body tone, colour pattern, shape, dimensions and opal type, from luminous white opal to dramatic black and boulder opal or glowing fire opal.
Every natural opal is individual. Availability depends on type, body tone, pattern, colour, stability, treatment, construction, shape and dimensions.
Enquire About Bespoke Options →Opal Questions
Play-of-colour is the shifting display of spectral colours seen in precious opal as the stone, light or viewing angle changes.
Black opal is opal with a dark body tone. When it is precious opal, that dark background can create exceptional contrast with its play-of-colour.
Boulder opal forms with ironstone host rock, which is intentionally retained as part of the cut gemstone and can create dramatic natural patterns.
No. Fire opal is named for its yellow, orange or red body colour. It may show play-of-colour, but many beautiful examples do not.
Solid opal is one piece of opal material. A doublet has an opal layer attached to a backing, while a triplet adds a transparent cap above the opal layer.
Opal can be worn regularly, but with a Mohs hardness around 5–6.5 it needs more protection from scratches, impacts and sudden temperature changes than harder gemstones.
