Laboratory-Grown Diamonds

A laboratory-grown diamond is carbon grown into the same crystal structure as a mined one. It is not a lookalike made of a different material, such as cubic zirconia. What sets it apart is origin: it was grown in a laboratory instead of forming deep underground.

There are two main ways to grow one. CVD, short for chemical vapor deposition, builds the crystal up layer by layer as carbon from a gas settles onto a thin seed plate inside a vacuum chamber. HPHT, short for high pressure, high temperature, surrounds a small seed crystal with carbon and puts it under intense heat and pressure in a press. Either way, the rough crystal is then cut and polished for jewelry.

The wording matters because it tells you what you are buying. The Federal Trade Commission’s Jewelry Guides say a stone made in a laboratory should carry a qualifier such as “laboratory-grown” or “laboratory-created,” placed immediately before its name and just as easy to read, so no one takes it for a mined stone. Wherever you shop, look for the same qualifier on the tag, the listing and the receipt, and ask if it is missing.

Cut, color, clarity and carat are the qualities to look at in a laboratory-grown diamond, as in a mined one. Knowing what each one means makes pieces easier to compare, however a report expresses them.

Independent laboratories, including the International Gemological Institute (IGI) and the Gemological Institute of America (GIA), issue reports for laboratory-grown diamonds, and those reports identify the stone as laboratory-grown. They do not all use the same terms: since October 2025, GIA’s report for colorless and near-colorless laboratory-grown diamonds classifies the stone as Premium or Standard instead of giving the color and clarity grades used for mined diamonds. Read what a report says instead of assuming a grade means the same thing everywhere.

Ask whether a piece comes with a report. If it does, look the report number up on the laboratory’s website and check that the shape and carat weight match the listing. Ask, too, whether the number is laser-inscribed on the stone’s girdle. The four qualities below cover the rest.

Newport Watch, Jewelry & Loan has been family-owned in Costa Mesa since 2007. Current pieces include laboratory-grown diamond earrings and tennis bracelets, and the store’s jewelry page shows each one with photos and a price. Inventory changes, so treat that page as a snapshot of what is there today, not a promise that a particular piece will still be available when you visit.

A photo can’t show everything, which is why the pieces can be seen at the Newport Blvd counter. Compare a pair of earrings side by side to see whether the stones match in size and brightness. Look along a tennis bracelet to check that the stones stay even from end to end and that the clasp closes securely. View any set stone from the side as well as from above; the side view shows the setting and how high the stone sits.