How Wholesale Diamond & Gemstone Buying Works in India: A Jeweller's Guide
Surat's cutting houses, Mumbai's Bharat Diamond Bourse, GST rates by stage, and why hallmarking doesn't apply to loose stones -- the India-specific trade mechanics.
India sits on both ends of the diamond supply chain — the world's largest cutting and polishing centre, and a major trading hub in its own right. See Wholesale vs retail: how the gem trade actually prices for how Chaos defines a genuine wholesale price; this piece covers the India-specific mechanics.
Surat cuts and polishes most of the world's diamonds by volume
Surat, Gujarat, is the world's largest diamond cutting and polishing hub by volume — a large share of the world's diamonds pass through Surat's workshops at some stage, even when the stone is ultimately sold somewhere else entirely. This is a cutting and manufacturing centre first; the trading side of the Indian market is concentrated elsewhere.
Mumbai's Bharat Diamond Bourse is the trading centre
The Bharat Diamond Bourse in Mumbai is the world's largest diamond trading complex by floor area, housing thousands of trading offices under one roof. It's the natural counterpart to Surat: stones are cut and polished in Surat, then traded through Mumbai.
GST applies at different rates by processing stage
India's GST on diamonds is tiered by how finished the stone is: rough diamonds attract a concessional 0.25%, cut and polished loose diamonds are taxed at 1.5% (in effect since July 2022), and finished diamond jewellery is taxed at 3% on the full invoice value, including making charges. Diamond and jewellery exports are zero-rated under GST.
BIS hallmarking applies to gold jewellery, not to loose stones
Bureau of Indian Standards (BIS) hallmarking is a purity certification scheme for gold jewellery sold in India — it has nothing to do with loose diamonds or coloured gemstones. A loose stone's authenticity and grading sit with its gemmological certificate, not a hallmark; conflating the two is a common confusion for buyers new to the Indian market.
What this means for a jeweller sourcing internationally
Knowing which Indian hub a stone actually passed through — and at what GST rate — explains a lot of the pricing you'll see quoted. It doesn't change what you should verify on the stone itself: see How to buy a loose diamond online without getting lost for that.
FAQ
What's the difference between Surat and Mumbai in the diamond trade?
Surat is the manufacturing centre — cutting and polishing by volume — while Mumbai's Bharat Diamond Bourse is the trading centre where cut stones change hands between dealers.
What GST rate applies to the loose diamond I'm buying?
Cut and polished loose diamonds are taxed at 1.5% GST; rough diamonds at a concessional 0.25%; finished jewellery at 3% on the full invoice value.
Does BIS hallmarking apply to my loose diamond or gemstone?
No — BIS hallmarking is a gold-purity certification scheme for finished jewellery. A loose stone's grading and authenticity are established by its own gemmological certificate instead.
Related reading
Jaipur, Bangkok, Colombo — the world's gem cutting hubs
What each market specialises in, how dealers price, and how to evaluate offers from each region remotely.
Wholesale vs retail: how the gem trade actually prices
Why one dealer's 'wholesale' is another's retail, and how Chaos forces transparent dealer pricing across the platform.
How Gemstones Are Priced: Colour, Clarity, Cut, Carat, Origin & Treatment
Coloured gemstones aren't priced like diamonds — colour usually matters more than clarity, and origin and treatment can swing value more than either.
Use Chaos as a stone sourcing layer
Browse verified dealer inventory, save options for clients, and connect live stones into your own sales workflow.