Man-Made Gemstones: The Complete Australian Guide

What are man-made gemstones?

Man-made gemstones are gem materials produced in a laboratory or factory rather than mined from the earth. The phrase covers several quite different things, and the difference matters for what you are paying for and how the stone must be described.

A synthetic or lab-created gemstone has essentially the same chemical composition, crystal structure and physical properties as its natural counterpart. A lab-created ruby is corundum (aluminium oxide, Al₂O₃) coloured by chromium, exactly like a natural ruby. A simulant only looks like another gem: cubic zirconia resembles diamond, but it is a different material with different hardness, weight and optics.

Treated stones are natural, not man-made, even though the treatment happens in a workshop; our guide to treated and untreated gemstones covers heating, oiling, fracture filling and diffusion. Some materials sit in two categories: moissanite in jewellery is lab-created silicon carbide (natural moissanite is far too rare and tiny to cut), and when it is set in place of diamond it is also a diamond simulant. If any of these words are new, the GemTrove jewellery glossary defines them, and our coloured gemstones hub covers the natural stones these materials are measured against.

Which lab-created gemstones are used in jewellery?

Only gems that are worth growing commercially get synthesised. Tanzanite, tourmaline and most garnets are rarely made in a lab because natural material is affordable enough; they are imitated with glass or other synthetics instead. The lab-created materials you will actually meet in jewellery are:

• Lab-created ruby and sapphire (corundum): the oldest and most common synthetic gems, made in red, blue, pink, yellow, orange-pink, colourless and colour-change versions. Mohs hardness 9.
• Lab-created emerald (beryl): grown by flux or hydrothermal methods and usually far cleaner than mined material. Compare the natural stone in our emerald gemstone guide.
• Lab-created alexandrite (chrysoberyl): shifts from bluish green in daylight to purplish red under warm indoor light. Natural alexandrite with a strong change is one of the rare collector gemstones, so most alexandrite in June birthstone jewellery is lab-created.
• Lab-created spinel: often made in colours that copy other gems, such as an aquamarine-blue used in birthstone pieces. That stone is synthetic spinel acting as an aquamarine simulant.
• Lab-created quartz: amethyst, citrine and ametrine. Natural quartz is inexpensive, so the price gap is small.
• Lab-created opal: first marketed in the 1970s; some modern lab opal contains resin and is softer than natural opal.
• Laboratory-grown diamond: made by HPHT or CVD in colourless and fancy colours, including pink and blue.
• Moissanite and cubic zirconia: man-made diamond simulants with their own properties.

If you are weighing a lab-created ruby against a mined one, our natural ruby guide explains what drives value in the natural stone: colour, origin, treatment and size. Those factors barely move the price of a lab-created stone, which is set mainly by the growth method and the quality of cutting.

How are man-made gemstones made?

Every method does the same basic job: it brings the right chemical ingredients together at the right temperature and lets atoms build a crystal, layer by layer. The methods split into two families. Melt methods (flame fusion, pulling, skull melting) are fast and cheap. Solution methods (flux and hydrothermal) are slow and expensive, but grow crystals more like natural ones.

Speed explains most of the price spread within man-made stones. A flame-fusion boule of several hundred carats can grow in a few hours, while a flux-grown crystal of lab-created ruby may take months and yield only a few cuttable carats. A short timeline: Auguste Verneuil published flame fusion in 1902, Jan Czochralski described pulling in 1916, flux-grown lab-created emerald reached the market around the 1930s–40s, General Electric produced reproducible lab-grown diamonds in 1954, cubic zirconia was mass-produced from the mid-1970s and moissanite entered jewellery in 1998.

Because lab-created stones share the natural gem's structure, they also share its refractive index, specific gravity and other gemstone properties. That is exactly why identification relies on growth features rather than simple tests.

Are man-made gemstones real gemstones?

It depends which kind you mean. A lab-created sapphire is real corundum: same hardness, same optics, same colour-causing elements. It is not natural, and it must always be described as lab-created or synthetic. A simulant is not the gem it imitates at all. The table compares a natural sapphire, a lab-created sapphire and a blue glass imitation.

Origin is one thing a lab stone can never have. Australia produces natural sapphire from the central Queensland fields around Anakie and Rubyvale and from New England in New South Wales, and most of the world's precious opal comes from Lightning Ridge, Coober Pedy and the Queensland boulder fields. Labs read trace elements and inclusions to work out where a natural stone formed, as our guide to how gemstone origin is determined explains; a lab-created stone simply has no geological story to read.

Size works the same way for natural and lab-created versions of one gem, because density is identical. Simulants differ: cubic zirconia (specific gravity 5.6–6.0) is much heavier than diamond (3.52), so a 6.5 mm round CZ weighs roughly 1.6–1.7 carats while a diamond of that spread is about 1 carat. Our page on carat versus size and density shows the maths.

How can you tell if a gemstone is lab-created?

Usually not by eye. The first hint is often that a stone looks too good for its price: rich colour, no visible inclusions and a large size. From there a gemmologist works through the evidence. These are the identification notes we use most:

• Curved striae: flame-fusion ruby and sapphire show curved growth bands, like the grooves on a record, under 10× magnification. Natural corundum shows straight, angular zoning that follows its hexagonal crystal.
• Gas bubbles: round or tadpole-shaped bubbles point to a melt product. Natural corundum does not contain them, although glass-filled natural rubies can show bubbles in the filler.
• Flux fingerprints and platinum platelets: wispy veils of trapped flux, sometimes with bright triangular or hexagonal metal flakes from the crucible, mark flux-grown lab-created ruby, sapphire and emerald.
• Chevron growth: hydrothermal lab-created emerald often shows zigzag growth and nail-head spicules (a tiny crystal capping a tube).
• Refractive index and density: flux-grown lab-created emerald reads about 1.560–1.563 with a specific gravity near 2.65–2.66, lower than most natural emerald. Flame-fusion spinel reads about 1.728 against about 1.718 for natural spinel, and shows strain in a polariscope.
• Spectroscopy: iron-rich natural Australian sapphires usually show a strong absorption line near 450 nm; lab-created blue sapphire generally does not. Labs confirm with FTIR, UV-Vis and trace-element analysis.
• Lab-created opal: a 'lizard-skin' or chicken-wire pattern face-up and columnar structure seen from the side, unlike the irregular patches of natural play-of-colour.
• Moissanite: doubled facet edges seen through the crown, and it can read as diamond on a basic thermal tester, so it needs a moissanite-specific test.

Laboratory-grown diamonds and high-quality flux or Czochralski stones can be very clean, so features may be absent; that is when the instruments described in our guide to scientific gemstone identification take over. Independent reports from labs such as GIA state 'synthetic' or 'laboratory-grown' clearly on the report.

Are man-made gemstones good for everyday rings?

A lab-created stone wears exactly as its natural equivalent does, because hardness and structure are the same. Hardness (the Mohs scale) measures scratch resistance; toughness measures resistance to chipping and breaking. Lab-created stones are sometimes a little tougher than included natural stones because they have fewer fractures, though flame-fusion material can carry internal strain.

Household dust contains quartz (Mohs 7), so anything below 7 dulls quickly on a hand. Our Mohs hardness explained page covers the scale, the guide to durability for everyday rings adds toughness and stability, and gemstones that suit daily wear ranks the natural options for an engagement ring.

Are man-made gemstones worth it?

They are worth it if you want a particular colour, size and clarity at a modest price, and you are comfortable with a stone that has no geological origin. They are not the right choice if the rarity and history of a mined stone are what you love. Prices vary widely by method and cutting quality, so treat these as rough guides only.

Resale is low for lab-created stones, and resale on natural stones is usually well below the retail price too, so choose either because you will enjoy wearing it. One Australian example: since the Argyle mine in Western Australia closed in 2020, natural Argyle pinks have become scarcer still, while laboratory-grown pink diamonds are widely available for a small fraction of the price. Both are legitimate choices, as long as each is described accurately.

Lab-created sapphire and alexandrite are popular centre stones for coloured gemstone engagement rings, where a strong, even colour in a 7–8 mm stone would cost far more in natural material.

How should lab-created gemstones be set and cared for?

Set and care for a lab-created stone exactly as you would the natural gem. Hard corundum and alexandrite suit claws; lab-created emerald and opal are safer in a bezel or a design that shields the edges. Our setting styles for diamonds and coloured stones compares claws, bezels and halos.

• Lab-created ruby, sapphire, alexandrite, spinel: warm soapy water and a soft brush; ultrasonic cleaners are generally fine for clean, unfractured stones.
• Lab-created emerald: mild soap only; skip ultrasonic and steam, as some are clarity-treated after growth.
• Lab-created opal: avoid harsh chemicals and heat, especially resin-containing material.
• Cubic zirconia: clean often; its surface collects grease and the edges abrade, so it may need repolishing or replacing after years of wear.

For stone-by-stone cleaning advice, see care instructions for each gemstone.

How to buy man-made gemstones: step by step

In Australia, the Australian Consumer Law prohibits misleading or deceptive conduct, so a lab-created stone should always carry its qualifier: 'lab-created', 'laboratory-grown' or 'synthetic', with equal prominence to the gem name. Trade names such as 'created ruby' should still make clear the stone is man-made.

1. Confirm the category. Ask whether the stone is natural, treated natural, lab-created, a simulant or assembled, and get it in writing on the invoice.
2. Ask the growth method. Flame-fusion and flux-grown lab-created stones differ a lot in price and appearance.
3. Check hardness for the job. Mohs 8 and above for a daily ring; softer materials for pendants and earrings.
4. Look at cutting quality. Cheap lab-created stones are often cut fast, with windows (washed-out centres) and uneven facets.
5. Request a report for valuable stones. Our guide to how a gem lab confirms identity explains what the report checks.
6. Plan the setting. Match claws or a bezel to the stone's toughness before you commit.