What Questions Should I Ask a Jeweller Before Buying a Diamond?
Ask about the grading report, the diamond's specific characteristics, the pricing basis, and the after-sale terms. The right questions reveal whether a seller is knowledgeable, transparent, and operating in your interest. A good jeweller will welcome these questions. A defensive or evasive response tells you something important.
About the Diamond's Documentation
"Does this diamond come with a grading report, and which laboratory issued it?" You want to hear GIA, HRD Antwerp, or IGI. If the answer is a lesser-known lab, ask how their grading compares to GIA. If there is no report, ask why — and consider whether you are comfortable buying without independent verification.
"Can I see the grading report before I decide?" This should be an immediate yes. If the seller wants to discuss the diamond first and share the report later, ask yourself why they would prefer that sequence.
"Can I verify the report number online?" Every report from GIA, HRD, and IGI is verifiable through the laboratory's online database. If a seller discourages you from checking, that is a concern.
About the Diamond Itself
"What are the exact grades — colour, clarity, cut, and carat weight?" Listen for specifics: "G colour, VS2 clarity, Excellent cut, 1.21 ct" is a good answer. "It's a really nice stone, very white, very clean" is not. Vague language often substitutes for data the seller would rather not disclose.
"Has this diamond been treated or enhanced in any way?" Treatments — such as laser drilling, fracture filling, HPHT colour enhancement, or coating — must be disclosed. They affect both durability and value. A reputable seller will answer this clearly and without hesitation.
"Can I see video or imagery of the diamond?" For online purchases, this should be available by default. For in-store purchases, ask to examine the diamond under standard lighting — not just the flattering spotlights of a jewellery display case.
"Does the diamond have fluorescence, and if so, how strong?" Fluorescence is documented on the grading report, but it is worth discussing. Strong or very strong fluorescence can occasionally cause a milky or hazy appearance, particularly in higher-colour diamonds. Ask the jeweller to explain how fluorescence affects this specific stone.
About Pricing
"How is this diamond priced relative to its grades?" This question signals that you have done research and expect a price that aligns with market values for the stated grades. A knowledgeable jeweller will be able to explain what factors influence the price — cut quality, specific clarity characteristics, fluorescence, and demand for the shape and size range.
"Are there additional costs I should know about — setting, sizing, shipping, insurance?" Get the full picture before committing. Ask whether the quoted price includes the setting or just the loose stone. For custom-made jewellery, ask about manufacturing timelines and any design-related costs.
About After-Sale Terms
"What is your return or exchange policy?" Understand the terms in advance. For custom-manufactured jewellery — such as engagement rings made to order — return policies are typically more limited than for off-the-shelf items. This is reasonable, but you should know the terms before you commit.
"Do you provide any warranty on the setting or metalwork?" Prong wear, rhodium plating on white gold, and other maintenance items vary by jeweller. Ask what is covered and for how long.
"Will you provide a detailed receipt or invoice that includes the diamond's specifications?" Your receipt should document the grading report number, laboratory, carat weight, colour, clarity, cut grade, and the metal and setting type. This documentation is essential for insurance purposes and future reference.
The Quality of the Answers Matters
The specific answers matter less than how they are given. A jeweller who answers openly, points you to the grading report, and welcomes comparison is demonstrating confidence in their product. A jeweller who deflects, speaks in generalities, or pressures you to decide quickly is signalling that scrutiny is not in their interest.
Learn More
- Reports 101 — understanding what a grading report tells you
- Transparency & Disclosure — what responsible sellers should provide
- The 4Cs Overview — the grading framework every buyer should understand
- Fluorescence — when it helps, when it hurts, and how to evaluate it