Moissanite found being passed off as LGDs in jewelry

Moissanite is not a laboratory-grown diamond. Moissanite is silicon carbide, while a laboratory-grown diamond is diamond material consisting predominantly of crystallized carbon. Because both stones can conduct heat efficiently and may look similar to an untrained viewer, some basic thermal diamond testers can register moissanite as diamond. Reliable verification requires more than appearance or a single handheld-tester result.

The concern received renewed attention after a January 30, 2026 Times of India report cited the Indian Diamond Institute in Surat as detecting moissanite in jewelry represented as containing laboratory-grown diamonds. An institute representative reportedly said its gemological laboratory was finding at least one such jewelry item per week.

That observation is important, but it should be understood accurately. It reflects cases reaching one testing laboratory; it does not establish how common the practice is throughout India or the global jewelry market. Established manufacturers and responsible jewelers use sourcing controls, screening and documentation to reduce the risk of undisclosed substitution.

The problem is not moissanite itself. Moissanite is a durable, attractive gemstone with its own appearance, value and appeal. The problem arises when a seller describes it as diamond or fails to disclose what the buyer is actually receiving.

What Was Reported in Surat?

Surat is a major center for diamond cutting, polishing and laboratory-grown diamond manufacturing. According to the January 2026 report, jewelry submitted to the Indian Diamond Institute’s gemological laboratory had included instances in which moissanite was used in pieces represented as laboratory-grown diamond jewelry.

The report attributed the following observations to representatives of the institute and the Surat Jewellery Manufacturers Association:

• The testing laboratory was reportedly identifying at least one such jewelry piece per week.
• Moissanite should not be described or sold as diamond.
• Some documentation practices may confuse buyers by applying diamond-like color and clarity terminology to moissanite without making the material identity sufficiently clear.
• Established manufacturing facilities generally use quality-control testing and documentation to prevent substitutions.

This is a consumer-disclosure issue. It should not be used to imply that all Surat manufacturers, laboratory-grown diamond sellers or moissanite businesses engage in dishonest practices.

A responsible seller should state the gemstone identity clearly on the product page, invoice and any accompanying report. Terms such as “diamond alternative,” “diamond-like” or “diamond equivalent” should not be presented in a way that causes a reasonable buyer to believe moissanite is diamond.

Moissanite vs Laboratory-Grown Diamond: Key Differences

Both gemstones can be produced in controlled environments and both can be suitable for frequently worn jewelry. Their laboratory origin does not make them interchangeable.

Factor Laboratory-grown diamond Moissanite Material Diamond crystal consisting predominantly of carbon Silicon carbide Gem category Diamond A separate gemstone and diamond simulant Mohs hardness 10 Commonly listed at approximately 9.25 Refraction Singly refractive Doubly refractive Fire Balanced diamond fire and white-light return, depending strongly on cut Often shows stronger rainbow-colored flashes Basic thermal tester Normally registers as diamond May also register as diamond How it is commonly listed Actual carat weight and millimeter measurements Often listed by millimeter size or diamond-equivalent weight Typical price position Generally costs more than comparably sized moissanite Generally more affordable, although pricing varies by seller and quality Correct sales description Laboratory-grown or laboratory-created diamond Moissanite

For a broader appearance, durability and price comparison, read the Rosec Jewels guide to moissanite versus laboratory-grown diamond.

Does moissanite look exactly like diamond?

It can look diamond-like, particularly in small sizes or bright retail lighting. However, the optical appearance is not identical.

Moissanite’s higher dispersion commonly produces more visible rainbow flashes. Diamond often displays a different balance of white brilliance, dark-and-light contrast and colored fire. These differences may be easier to notice in larger stones, certain cuts or particular lighting environments.

Appearance alone is not a reliable identification method. A well-cut moissanite can appear more diamond-like than a poorly cut diamond, and jewelry-store spotlights can make visual comparison difficult.

Are both suitable for everyday jewelry?

Both materials are highly resistant to scratching and may be suitable for rings, earrings, necklaces and bracelets. Diamond is harder, but hardness is only one part of durability. Either gemstone can chip, loosen or become damaged if it is struck, poorly set or worn during high-impact work.

The security of the setting, prong condition, stone shape, metal thickness and workmanship all affect long-term wear.

Can Moissanite Pass a Diamond Tester?

Yes. Some traditional handheld testers measure thermal conductivity. Diamond conducts heat efficiently, but moissanite also has high thermal conductivity. The US Federal Trade Commission warns that thermal testers used to distinguish diamond from cubic zirconia may incorrectly register moissanite as diamond.

This means a tester that beeps or displays “diamond” has not necessarily completed the identification.

Thermal testers

Thermal testers measure how rapidly heat moves away from the probe. They are useful for separating diamond from many common simulants, but they may not reliably separate diamond from moissanite.

Combination thermal and electrical testers

Newer devices may test both thermal and electrical conductivity. These can improve screening because many moissanites conduct electricity differently from most diamonds.

However, handheld instruments are screening tools, not universal final-identification systems. Results may be affected by:

• Stone size.
• Probe placement.
• Metal contact in a mounted setting.
• Stone temperature.
• Surface dirt or moisture.
• Calibration.
• Unusual properties in certain laboratory-grown diamonds.
• Operator experience.

A “refer,” uncertain or conflicting result means that further testing is needed. It does not prove that a stone is fake.

How Professionals Distinguish Moissanite from Diamond

A qualified gemologist may use several observations and instruments rather than relying on a single result.

Double refraction

Diamond is singly refractive, while moissanite is doubly refractive. Under magnification, doubling of certain facet junctions may be visible through moissanite.

Double refraction is not unique to moissanite, and it may be difficult to observe depending on the viewing direction, cut, stone size and setting. It should be treated as one diagnostic clue rather than a complete identification.

Dispersion and visual pattern

Moissanite commonly produces stronger spectral or rainbow flashes. Diamond may display a more familiar mixture of white brightness, contrast and fire. Cut quality strongly influences both appearances.

Electrical conductivity

Some instruments use electrical conductivity to help separate moissanite from diamond. As with any screening test, unusual results should be investigated rather than treated as a final verdict.

Microscopic examination

Magnification can help a gemologist assess facet-junction doubling, polish, inscriptions, inclusions and growth-related features.

Spectroscopic analysis

Professional laboratories may use infrared, Raman, ultraviolet-visible or photoluminescence spectroscopy and other specialized instruments. These methods examine material properties that cannot be reliably judged by appearance alone.

GIA reported identifying synthetic moissanite with a fraudulent diamond inscription through standard testing, microscopic examination and spectroscopic analysis. The stone showed obvious double refraction, and infrared and Raman results confirmed that it was moissanite.

Readers comparing visual identification with instrument-based screening may also find Rosec Jewels’ guide on whether a jeweler can identify a laboratory-grown diamond by eye useful.

How to Verify a Diamond Grading Report

People often call the document a certificate, but recognized gemological laboratories generally issue a grading or identification report. A report is valuable only when it is authentic and corresponds to the actual stone or jewelry item.

1. Use the laboratory’s official verification service

Enter the report number directly on the issuing laboratory’s official website. Do not rely only on a QR code supplied by the seller, because a fraudulent code could direct you to an imitation page.

For commonly encountered reports, use the official GIA Report Check or IGI report-verification service.

1. Compare more than the report number

A valid report number does not automatically prove that the physical stone is the one described. Compare:

• Natural or laboratory-grown origin.
• Gemstone identity.
• Shape and cutting style.
• Carat weight.
• Millimeter measurements.
• Color and clarity information.
• Polish and symmetry.
• Fluorescence where reported.
• Growth method or treatment comments where included.
• Laser-inscription details.

Measurements are especially useful. Two stones can have similar stated weights but noticeably different dimensions because diamond and moissanite have different densities.

1. Confirm what the report covers

Ask whether the report covers:

• One loose center stone.
• The complete mounted jewelry item.
• The center stone only.
• All accent stones.
• The metal type and purity.

A report for one center stone should not be assumed to identify every halo, pavé or side stone in the piece.

1. Understand mounted-jewelry limitations

IGI explains that finished-jewelry reports may identify mounted gemstones and provide center-stone measurements and grading information as the mounting permits. A setting can obstruct parts of a stone and limit precise weight, clarity, color or inscription observations.

If the most complete possible analysis is required, the laboratory may recommend testing the stone loose. Removing a stone should be performed only by an appropriate professional because unsetting carries cost and damage risk.

Can a Laser Inscription Be Fraudulent?

Yes. A laser inscription is a useful identification aid, but it should not be accepted without checking the report and stone together.

GIA documented a 1.02-carat synthetic moissanite carrying a fraudulent GIA report number. The number belonged to a genuine natural diamond of the same stated weight, but the moissanite’s measurements did not match the genuine report. GIA also observed differences in the inscription’s appearance and confirmed the material through gemological testing.

This case demonstrates why verification should include:

1. Checking the report number on the official laboratory website.
2. Comparing the stone’s measurements with the report.
3. Inspecting the font, placement and condition of the inscription.
4. Confirming that the stone itself tests as the material described.

An inscription helps link a stone to documentation, but it does not replace material identification.

Seven Steps to Verify a Loose Laboratory-Grown Diamond

1. Read the description carefully. It should clearly state “laboratory-grown diamond” or “laboratory-created diamond.” It should not rely only on unclear abbreviations or phrases such as “diamond alternative.”

2. Request the grading report. Obtain the complete report number and issuing laboratory before the return period expires.

3. Verify the report independently. Type the laboratory’s official website address yourself and retrieve the digital report.

4. Compare weight and dimensions. Ask the seller or gemologist to confirm that the stone’s measurements match the report.

5. Inspect the laser inscription where present. The number should correspond to the verified report, but the material should still be tested.

6. Use appropriate screening equipment. Do not accept only a basic thermal-tester result when moissanite is a concern.

7. Obtain written identification. The invoice should name the gemstone as laboratory-grown diamond and include the report number when applicable.

How to Verify a Mounted Ring or Jewelry Item

Mounted jewelry presents additional challenges because metal, prongs, bezels and nearby stones may interfere with observation and testing.

Ask whether every stone was screened

A ring may include:

• A laboratory-grown diamond center stone.
• Moissanite accents.
• Diamond accents.
• Cubic zirconia or other simulants.
• A combination of materials that was intentionally designed and correctly disclosed.

Mixed-gemstone jewelry is not a problem when every material is described accurately. The issue occurs when the invoice or product page represents all stones as diamond while undisclosed simulants are present.

Request stone-by-stone disclosure

The product description or invoice should identify:

• Center-stone material.
• Side-stone or accent material.
• Approximate or actual weights.
• Number of stones.
• Report coverage.
• Any treatment information that requires disclosure.

Use a qualified professional

Ask whether the jeweler or gemologist can screen mounted stones and what instruments will be used. A basic thermal tester alone is not sufficient when distinguishing diamond from moissanite.

Understand the difference between identification and appraisal

A gemstone-identification service determines what the stone is. An appraisal estimates value for purposes such as insurance, resale or estate documentation.

Some qualified appraisers provide both services, but an appraisal document does not automatically prove that comprehensive gemological testing was completed. Ask specifically for material identification.

Warning Signs Before Buying

No single warning sign proves fraud, but several together should lead to further questions.

• The seller uses “diamond” without stating whether it is natural or laboratory-grown.
• The product title says laboratory-grown diamond, while the specifications say moissanite, simulant or diamond alternative.
• The center-stone size is stated only as “carat equivalent” without the actual material identity.
• The price is unusually low compared with stones of genuinely comparable specifications.
• The seller refuses to provide the report number before purchase.
• The report number cannot be verified on the issuing laboratory’s official website.
• The report measurements do not match the stone.
• The seller relies only on a handheld thermal-test demonstration.
• The invoice says “white stone,” “created stone” or “diamond-like stone” instead of naming the material.
• Only the center stone is documented, but the seller claims that every accent is diamond.
• The return period is too short to arrange independent verification.
• The seller discourages third-party inspection.

Be careful with “diamond-equivalent weight”

Moissanite may be marketed according to the diameter of a diamond with a similar face-up size. For example, a seller may use a phrase such as “one-carat diamond equivalent.” That does not mean the moissanite has an actual weight of one carat or that it is a diamond.

The listing should state:

• That the stone is moissanite.
• Its millimeter dimensions.
• Its actual weight where supplied.
• Whether a diamond-equivalent comparison is being used.

What the Invoice and Product Page Should Disclose

Before paying, confirm that the written documentation includes:

• The full gemstone name.
• Whether the diamond is natural or laboratory-grown.
• Center-stone and accent-stone identities.
• Carat weight or millimeter dimensions.
• Metal type and purity.
• Report number and issuing laboratory where applicable.
• Known treatments where disclosure is required.
• Return, exchange and warranty terms.
• Repair and resizing conditions.

Save a PDF or screenshot of the product page at the time of purchase. Online descriptions can change, so the version you relied upon may become important if a disagreement arises.

What to Do If You Suspect Misrepresentation

Stay calm and preserve the condition of the jewelry. Do not attempt destructive home tests, remove the stone yourself or alter an inscription.

1. Preserve the evidence

Keep:

• The jewelry.
• Original packaging.
• Invoice and receipt.
• Product-page screenshots.
• Advertisements and messages.
• Grading report.
• Payment records.
• Return and warranty policies.

1. Obtain independent identification

Use a recognized laboratory or a qualified independent gemologist with suitable equipment. Request a written document that states:

• The material identified.
• The testing limitations.
• Whether the item was tested mounted or loose.
• Which stones were examined.
• Whether the report or inscription matched.

1. Contact the seller in writing

Describe the discrepancy factually and attach the independent findings. State the remedy you are requesting, such as:

• A full refund.
• A correctly described replacement.
• A price adjustment when you knowingly choose to retain the item.
• Reimbursement of reasonable testing costs where appropriate.

1. Act within the return and payment-dispute deadlines

Review the seller’s return period and the dispute rules for your payment method. Deadlines may differ by card issuer, payment provider and country.

1. Escalate when necessary

When the seller does not resolve a documented misrepresentation, consider contacting the relevant consumer-protection authority, marketplace, payment provider or legal professional in your jurisdiction.

This section provides general consumer information and is not legal advice. Consumer rights and remedies vary by location.

Moissanite Can Still Be a Responsible and Beautiful Choice

Moissanite should not be treated as a defective diamond. It is a distinct gemstone valued for intense fire, strong scratch resistance and accessible pricing.

A buyer may intentionally choose moissanite because:

• Its rainbow fire appeals to them.
• They want a larger visual size within their budget.
• They prefer a laboratory-created, non-mined center stone.
• They want durable jewelry for frequent wear.
• Diamond identity is not personally important.

A buyer may instead choose a laboratory-grown diamond because:

• They specifically want diamond material.
• They prefer diamond’s optical appearance.
• They want a report documenting diamond origin and quality.
• They value diamond hardness and traditional diamond terminology.
• They want the jewelry represented and insured as diamond.

The correct choice depends on the buyer’s preferences. Transparency allows both gemstones to be appreciated for what they actually are.

Frequently Asked Questions

Is moissanite a laboratory-grown diamond?

No. Moissanite is silicon carbide, while a laboratory-grown diamond consists predominantly of carbon in a diamond crystal structure. Both may be produced in controlled environments, but they are different gemstone materials and must be described separately.

Can moissanite pass a diamond tester?

Yes. Some basic thermal testers may register moissanite as diamond because both materials conduct heat efficiently. A thermal result should be followed by additional screening or professional gemological testing when material identity matters.

Can a combination tester identify moissanite correctly?

A combination thermal and electrical tester may improve screening, but no handheld result should be treated as universally conclusive. Stone size, temperature, setting contact, calibration and unusual material properties can affect results.

Can you tell moissanite from a laboratory-grown diamond by eye?

Not reliably in every case. Moissanite often shows stronger rainbow fire, while diamond may display a different balance of white light and contrast. Cut, lighting, stone size and setting can make visual identification uncertain.

Can a jeweler test a stone while it is mounted?

Often, yes. Appropriate instruments can screen many mounted stones, but metal and setting design may restrict access or interfere with testing. A laboratory may provide information only as the mounting permits or recommend testing the stone loose.

Does a GIA or IGI report guarantee that the physical stone matches?

No report should be accepted without checking the actual item. Verify the report number on the laboratory’s official website and compare the stone’s shape, weight, measurements, origin, inscription and other reported details.

Can a moissanite carry a fraudulent diamond inscription?

Yes. GIA has documented synthetic moissanite bearing a fraudulent GIA report inscription. This is why buyers should compare measurements and material identification rather than checking only whether a number appears on the girdle.

Does every stone in a ring have its own report?

Usually not. A report may cover only the center stone or may describe the finished jewelry as the setting permits. Ask whether the accent stones were independently screened and ensure their material identity appears on the invoice.

Is a jewelry appraisal the same as a grading report?

No. A grading or identification report documents gemstone characteristics and identity. An appraisal estimates value. Some appraisers provide gemological identification, but buyers should confirm what testing was performed.

Is moissanite less durable than a laboratory-grown diamond?

Moissanite is slightly less hard than diamond but remains highly resistant to scratching and suitable for frequently worn jewelry. Either stone can chip or loosen depending on impact, shape, setting and maintenance.

Why does moissanite show more rainbow sparkle?

Moissanite has higher dispersion than diamond, meaning it separates white light into spectral colors more strongly. This can create prominent rainbow flashes, particularly in larger stones and bright lighting.

Is moissanite fraud when it is sold as a diamond alternative?

Not when the product clearly states that the stone is moissanite. The problem occurs when the seller represents moissanite as diamond, hides the material identity or uses confusing wording that misleads the buyer.

What should I do immediately after receiving expensive jewelry?

Check the product against the invoice, verify any laboratory report online, inspect the return deadline and arrange independent identification when the purchase value or emotional significance justifies it. Complete these steps before resizing or altering the jewelry.

Sources and Further Reading

• Times of India: Moissanite Found Being Passed Off as LGDs in Jewellery
• GIA: Synthetic Moissanite with a Fraudulent GIA Inscription
• GIA: Simulants, Moissanite and Laboratory-Grown Diamonds
• FTC: Advertising Diamonds, Gemstones and Pearls
• FTC Consumer Advice: Buying Gemstones, Diamonds and Pearls
• IGI: Laboratory-Grown Diamond Reports and Finished-Jewelry Identification
• IGI: Report Verification

Editorial disclaimer: This article provides general gemstone-identification and consumer information. A visual comparison or basic handheld test cannot replace professional gemological identification. Consumer rights, reporting procedures and legal remedies vary by jurisdiction.