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Black lab-grown opal, round cabochon
Black lab-grown opal, round cabochon, side view
Black lab-grown opal, round cabochon, 45° view
Round cut size guide: every size shown to scale on a finger, ear and neck, with a mm ruler

Lab-Grown Black Opal – Round Cabochon

Sale priceDhs. 1,070.00

Colour:

Shape: Round

Size:
Gemstone size guide

Carat is a measure of weight, not size. Some gemstones are denser than others, so the same carat weight looks different from one gem to the next: a 1 ct sapphire is a little smaller than a 1 ct diamond, and a 1 ct emerald is noticeably larger. That is why we size our gemstones in millimetres. The carat weights we show are close estimates.

One carat, four gemstones

Diamond
6.5 mm
Sapphire & ruby
6.1 mm
Alexandrite
6.2 mm
Emerald & aquamarine
6.9 mm

Round stones of 1 carat, drawn to scale with each other. Actual size on screen depends on your device.

Round stones: approximate carats by size

Size Diamond Sapphire & ruby Alexandrite Emerald & aquamarine
4 mm 0.2 0.3 0.3 0.2
5 mm 0.5 0.6 0.5 0.4
6 mm 0.8 1.0 0.9 0.7
7 mm 1.3 1.5 1.4 1.0
8 mm 1.9 2.3 2.1 1.5
9 mm 2.7 3.3 3.0 2.2
10 mm 3.7 4.5 4.2 3.0

Approximate weights for well-proportioned round brilliant stones. Emerald and aquamarine are both beryl, so they weigh almost the same at the same size.

Our shapes at about one carat

Round
6 mm · ~1.0 ct
Oval
7×5 mm · ~0.9 ct
Cushion
6×6 mm · ~1.2 ct
Pear
8×5 mm · ~0.9 ct
Emerald
7×5 mm · ~1.1 ct
Radiant
7×5 mm · ~1.1 ct
Princess
6×6 mm · ~1.3 ct
Asscher
6×6 mm · ~1.2 ct
Marquise
10×5 mm · ~1.1 ct
Heart
6×6 mm · ~1.1 ct
Trillion
7×7 mm · ~1.2 ct
Baguette
9×4.5 mm · ~1.1 ct

Lab-grown sapphire and ruby, drawn to scale with each other. Every shape is listed with its size in millimetres and an approximate weight.

Choosing your size

  • Go by millimetres. Two stones of the same carat weight can look quite different in size, depending on the gem and the shape. Elongated shapes such as oval, pear and marquise look larger face-up than a round stone of the same weight.
  • Exact weight. Each stone is cut to order, so its final weight can vary slightly from the estimate. If you add an IGI or GIA certificate, it records the measured weight.
  • Having it set. Our solitaire ring and pendant settings take stones up to 5 ct. For larger stones we make the setting to order and quote individually.
  • Matching a stone you already have? Send us its measurements in millimetres and we will cut to match. Ask us about a custom cut.

Certificates are charged at the lab’s fee: IGI Dhs. 164, GIA Dhs. 438. Grading adds up to 3 weeks. Need a different size or shape? We cut to your specification.

Have it set

We make your piece around this stone in yellow, white or rose gold (9K, 14K or 18K) or platinum, in one of our designs or your own. Made to order · Estimated dispatch in about 6 weeks.

Solitaire ring Setting from Dhs. 3,016, in the metal of your choice Solitaire pendant with chain Setting from Dhs. 1,919, in the metal of your choice Your own designBespoke service · no-obligation consultation

Free Shipping, Free 30-Day Returns

A lab-grown black opal polished as a round cabochon: a dark body lit with vivid flashes of blue, green and red. Each stone is cut to order in the calibrated size you choose, so it fits a standard setting for a ring, pendant or earrings. Opal is October's birthstone.

Gemstone Lab-grown opal
Colour Dark body with play-of-colour
Cut Round cabochon
Sizes 5 mm to 14 mm, calibrated
Weight Approximate, shown with each size. The exact weight depends on the proportions of your stone.
Hardness About 5.5 to 6.5 on the Mohs scale. Best for pendants and earrings, or a protective setting for a ring worn every day.
Dispatch Cut to order. Dispatched in about 14 days.
Returns Free 30-day returns with a prepaid label.

Need a different size or shape? We cut to your specification. Ask us about a custom cut.

Image for illustration. Every stone is cut to order.
Black lab-grown opal, round cabochon
Lab-Grown Black Opal – Round Cabochon Sale priceDhs. 1,070.00

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