Black opal is the top of the opal world, and the name misleads almost everyone who hears it for the first time. It does not mean the stone is black. It means the background the colour sits against is dark — and because colour reads far more vividly against dark than against light, black opal produces the most dramatic play-of-colour of any opal there is.

The stone

2.35 carats, which is 2.58 ratti. Shape: oval cabochon. Origin: Australia. Rs. 11,750, about Rs. 5,000 per carat, reference GS-000576.

What "black" actually means

Opal is graded on a body tone scale that runs from N1, the darkest, through to N9, the lightest. Black opal occupies the dark end; the milky material most people picture sits at the light end. Same mineral, same play-of-colour mechanism — microscopic silica spheres diffracting light — but a different backdrop.

The practical effect is straightforward. Against a pale background, light scatters and the colour reads as soft and milky. Against a dark one, there is nothing to dilute it, so the same green or orange flash looks electric. That is the entire reason black opal commands the prices it does.

Judging a black opal

• Brightness first, as always. A dark body tone with weak colour is not a bargain — it is a dull stone. Brightness decides value in every opal, black included.
• Which colours fire. Red against a dark background is the most prized combination in opal. Orange follows, then green, then blue.
• Coverage. Colour across the whole dome, not a bright patch with dead ground around it.
• Angle range. Tilt it slowly. Good material keeps producing colour through a wide arc.
• Natural dark tone, not an applied one. Covered below, and it is the question that matters most at this price.

The treatment question

Because dark body tone is worth so much more, there is a long-standing trade in darkening light opal — smoke treatment and sugar-acid treatment both do it, and both are permanent. A treated stone is still natural opal; it is simply not naturally dark, and it is worth a fraction of an untreated black opal.

We have not had this stone tested, so our specification sheet reads "treatment not tested" rather than claiming the tone is natural. At this rate that is worth settling: independent laboratory testing can be arranged before dispatch, or you can have it done yourself after delivery, since you pay the rider only once the parcel is open and the seven-day return window runs from delivery. Our lab-certified opal page explains the process.

Solid, not a doublet

This matters doubly with black opal, because a doublet — a thin slice of opal glued to a dark backing — mimics exactly the effect black opal is prized for. We sell solid natural opal. Look at any opal edge-on for a straight glue line where layers meet. Our real versus fake opal guide shows what to look for.

Care

Opal is 5.5 to 6.5 on the Mohs scale and holds water in its structure. Soft damp cloth only — never ultrasonic or steam. Keep it out of prolonged direct sun and dry heat, which can craze the surface. Ask for a bezel setting rather than claws.

Ordering

One piece only. Flat Rs. 500 delivery anywhere in Pakistan, insured and tracked, dispatched in one to two working days. Cash on Delivery, seven days to return it unused. Measurements on request — WhatsApp +92 308 887 3888. More in the Australian opal collection.

This particular stone

This listing is one natural australian opal with a weight of 2.35 Carat. Its price is Rs. 11,750 — roughly Rs. 5,000 for each carat. Origin: Australia. Treatment: treatment not tested. Quote reference GS-000576 when you message us about it. The photographs show this exact stone, so what arrives at your door is the piece you chose on screen.

Between two and six carats is the range most people choose for a gents' ring or a noticeable pendant. Here colour drives the price more than size does, which is why two stones of near-identical weight can be priced very differently.

Whoever you buy australian opal from, make sure of three things: the stone is natural rather than lab-grown, glass or glass-filled; any treatment is stated in writing; and the weight quoted is the weight of the finished stone. We check every australian opal for those three points before it is listed, a certificate is available on request, and because you pay on delivery you can look at the stone — or have it tested — before any money changes hands.

We sell natural stones only and inspect each one before it is listed. Treatment for this stone: Treatment not tested. Certificate available on request. As general background (not a statement about this stone): Solid opal is usually untreated; some opal is smoke- or sugar-treated, and doublets/triplets exist — we sell solid natural opal. Ask us on WhatsApp and we will tell you what we know about this exact stone; independent lab testing is available on request.

A certificate of authenticity is available on request for this stone, and independent laboratory testing can be arranged. Because you pay on delivery, you can also take the stone to a lab of your choice within the 7-day return window. Read more on our authenticity page.