The most useful thing a buyer can do before paying is to ask a short list of specific questions and keep the answers. Good sellers answer them without hesitation, because the answers are on their invoices already. Poor sellers deflect, generalise or refuse — and the deflection is the information. These questions apply to any seller, in any market, and none of them requires the buyer to know anything about gemmology.
About the article
What exactly is it? The species and variety for a stone (natural corundum, ruby); the mukhi count, origin and size for a Rudraksha. Not "a beautiful ruby" — the mineral name.
Is it natural, synthetic or an imitation? For a stone, all three words should be understood by the seller. For a Rudraksha: are all the faces natural, or have any been carved or improved?
Has it been treated? With what, and how much? Heating, filling, oiling, dyeing, diffusion, irradiation, coating, stabilisation. "No" is an answer; "I don't know" is an answer that should be on the invoice too. Natural, synthetic or simulant.
What does it weigh, and what are its dimensions? In carats or grams, and millimetres, for this specific article. Ratti, carat and gram.
Where is it from? Stated as the seller's claim, and understood as such. Can a laboratory tell where a gemstone came from?.
Is this the article in the photograph? Not a stock image.
About the paperwork
Is there a laboratory report? From which laboratory? What is the report number? So that you can verify it directly with the laboratory, not through the seller. How online report verification works.
Is the laboratory independent of you? A direct question deserving a direct answer. A seller's in-house certificate is the seller's description; a report from an affiliated laboratory should be disclosed as such.
Will you put the description — species, natural/synthetic, treatment, weight, origin claim — on the invoice? The single most protective question. A written description is what a laboratory report is compared against and what a return claim rests on.
About the transaction
What is the return window, and does it allow time for independent testing? Two weeks minimum. A return window that closes before a laboratory can examine the article is not a return window.
What happens if an independent laboratory finds the article is not as described? Full refund, including any testing fee, is the answer of a confident seller.
Is the price for this article, or for a category? Fine gemstones are priced individually. A "per carat" price for a stone you have not seen is a price for a category.
Can I have it tested before completing the purchase? Many sellers will allow a stone or bead to go to a laboratory on deposit, or will accept testing within the return window. A flat refusal is informative.
About the claims
What does "certified" mean on this listing? Which laboratory, which tests, which findings.
What does "energised" / "siddha" / "activated" mean, and what evidence supports it? These are not testable properties; a seller who leads with them should also be able to answer the questions above. Energised and siddha claims versus testing.
Why is the price what it is? A seller who can explain the price in terms of size, quality, treatment and origin has thought about it. One who cannot is quoting a number.
Keeping the answers
Screenshots of listings and messages; the invoice with the description on it; the certificate and its number; photographs of the article on arrival. Together with a laboratory report, these are the documents that resolve any dispute. Documentation and insurance.
Frequently asked questions
Will asking these questions offend a good seller?
No. A good seller has the answers ready and is glad to be asked, because it distinguishes them from sellers who do not.
What if the seller answers verbally but not in writing?
Ask again in writing. A seller willing to say it but not write it knows the difference between the two.
Do I need to ask all of these for an inexpensive item?
Scale to the price. For a cheap bracelet, "what is it and is it dyed?" is enough. For anything significant, the full list.
The seller says the laboratory does not do online verification. What then?
Contact the laboratory directly by telephone or email with the report number. If the laboratory cannot be reached, the certificate cannot be verified.
What if the answers are all good and the article still tests badly?
Then you have a written description, a report contradicting it, and a return window. That is a strong position, and most sellers refund in it.