Company lists · Data refreshed November 2026

Top 25 Diamond authentication services worldwide

RevenueBase identified 1,128 company matches for diamond authentication services worldwide as of November 2026 and tracks 13,810 professional contacts across them, including 3,112 with verified work emails. The United States is the largest market and New York the largest hub.

This list covers company matches for diamond authentication services worldwide, found by RevenueBase SmartSearch using the meaning of business descriptions in its company graph at Exact. Ranked by professionals tracked, largest first. Rows show recorded descriptions where available, Exact search membership and the snapshot date. Data refreshed November 6, 2026. Country and city lists for diamond authentication services follow the table.

Published by RevenueBase, a B2B data infrastructure company. This list was built with RevenueBase SmartSearch, the natural-language company search RevenueBase customers use to build their own targeted lists and unlock verified emails and direct dials at the companies on them. How these lists are built and judged.

How to read this list RevenueBase SmartSearch · Exact Recorded Nov 6, 2026 How this list was built
1,128Companies
13,810Contacts tracked
3,112Verified emails
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The 25 largest diamond authentication services worldwide

Ranked by team size
Top 25 of 1,128 company matches for diamond authentication services worldwide, ordered by professional contacts tracked in RevenueBase, largest first. Recorded Nov 6, 2026. The RevenueBase SmartSearch column shows Exact match membership in this saved search. Click a contact count to view that company's people. Totals use company locations recorded by RevenueBase; the displayed preview is a smaller selection.
#CompanyRevenueBase SmartSearchHeadquartersEmployeesContacts
1Exact matchNew York, NY, United StatesHQ recorded Nov 6, 2026501-1,000985 contacts →

Exact match

“Blue Nile was founded in with the idea that the diamond and engagement ring business was ready for innovation.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
2Exact matchNew York, CA, United StatesHQ recorded Nov 6, 2026501-1,000385 contacts →

Exact match

“IGI, a Blackstone portfolio company, is the world’s largest independent provider of gemological services.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
3Exact matchMumbai, IndiaHQ recorded Nov 6, 20261,001-5,000262 contacts →

Exact match

“OUR HERITAGE: The Asian Star group represents a rich heritage of values, skills and experience, amassed over five decades in the diamond industry.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
4Exact matchAntwerp, BelgiumHQ recorded Nov 6, 2026201-500260 contacts →

Exact match

“HRD Antwerp is the leading authority when it comes to Diamond Grading, Jewellery Grading and Education.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
5Exact matchHod Hasharon, IsraelHQ recorded Nov 6, 2026501-1,000252 contacts →

Exact match

“Since 1988, Sarine Technologies has been the leading technology company in the worldwide diamond domain, providing multi-disciplinary products based on cutting-edge technology to…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
6Exact matchNew York, United StatesHQ recorded Nov 6, 202651-200210 contacts →

Exact match

“The Rapaport Group is an international network of companies providing first class, added value services that support the development of free, fair, efficient and competitive…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
7Exact matchMumbai, IndiaHQ recorded Nov 6, 20261,001-5,000208 contacts →

Exact match

“Dimexon Diamonds Ltd, with sales offices in all 4 corners of the globe, is one of the world’s leading diamond manufacturers.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
8Exact matchZoutleeuw, BelgiumHQ recorded Nov 6, 20261,001-5,000197 contacts →

Exact match

Recorded description not available.

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
9Exact matchNew York, NY, United StatesHQ recorded Nov 6, 202651-200194 contacts →

Exact match

“Founded in 2016 by a former BCG consultant frustrated with his own engagement ring buying experience, Rare Carat began with a mission to make diamond buying more transparent for…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
10Exact matchLondon, United KingdomHQ recorded Nov 6, 2026201-500193 contacts →

Exact match

“Peace of mind, Assured.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
11Exact matchHong KongHQ recorded Nov 6, 2026201-500181 contacts →

Exact match

“HEARTS ON FIRE® is a modern diamond jewelry brand renowned for the beauty of its signature cut diamonds.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
12Exact matchManhattan, United StatesHQ recorded Nov 6, 202651-200161 contacts →

Exact match

“Gemological Science International (GSI) is one of the largest gemological laboratories with 13 offices in the United States, India, UAE, Hong Kong and Thailand.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
13Exact matchİstanbul, TürkiyeHQ recorded Nov 6, 20261,001-5,000161 contacts →

Exact match

“Blue Diamond, 2004 yılında toptancı bir firma olarak, mücevher sektörüne pırlanta tedarik etmek ve sektörü pırlanta konusunda eğitmek amacıyla kuruldu.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
14Exact matchMumbai, IndiaHQ recorded Nov 6, 20261,001-5,000127 contacts →

Exact match

“A dream company started by three visionaries; Arvind Shah, Arun Shah and Dilip Shah in 1985, was then strengthened by Vasant Shah, Pravin Shah and Dilip Soni, bringing together…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
15Exact matchClearwater, FL, United StatesHQ recorded Nov 6, 202651-200121 contacts →

Exact match

“Founded by Keith Leclerc in 1981, International Diamond Center began as a jewelry wholesaler.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
16Exact matchMumbai, IndiaHQ recorded Nov 6, 20261,001-5,000110 contacts →

Exact match

“To join our family, fill this form for us to know you better - https://forms.gle/mMD8d1hP3NHWJmr59 Founded by brothers Mr.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
17Exact matchMumbai, IndiaHQ recorded Nov 6, 2026501-1,00097 contacts →

Exact match

“Star Rays is a diamond manufacturer who are passionate about their products and solely focused on the diamond industry.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
18Exact matchDubai, United Arab EmiratesHQ recorded Nov 6, 202651-20082 contacts →

Exact match

“Stargems Group is an international diamond company that specializes in the sourcing and supply of the finest diamonds to customers across the world.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
19Exact matchAntwerp, BelgiumHQ recorded Nov 6, 2026501-1,00077 contacts →

Exact match

“Taché is a group of leading diamonds and jewelry companies operating in more than 15 counties over the five continents.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
20Exact matchMumbai, IndiaHQ recorded Nov 6, 202651-20076 contacts →

Exact match

“Divine Solitaires is the first & only loose solitaire brand in India which provides its consumer with the world’s finest & perfectly crafted solitaire diamonds in an organized &…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
21Exact matchMumbai, IndiaHQ recorded Nov 6, 20261,001-5,00075 contacts →

Exact match

“The Blue Star Diamonds group was established in Mumbai by Vasantlal Mehta in 1966.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
22Exact matchIndiaHQ recorded Nov 6, 2026501-1,00073 contacts →

Exact match

Recorded description not available.

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
23Exact matchBirmingham, United KingdomHQ recorded Nov 6, 202651-20066 contacts →

Exact match

“The Birmingham Assay Office was founded in 1773 to provide Assaying (testing) and Hallmarking of precious metal items (Gold, Silver, Platinum and Palladium) as required by the…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
24Exact matchUnited StatesHQ recorded Nov 6, 2026501-1,00065 contacts →

Exact match

Recorded description not available.

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
25Exact matchUnited StatesHQ recorded Nov 6, 202651-20061 contacts →

Exact match

“IDT is among the premier networks of Gemological Laboratories, which empowers and enables jewellers, jewellery brands, manufacturers, wholesalers, end-use customers and the masses…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase

Showing 25 of 1,128 diamond authentication services worldwide

See the full list, filter by size, metro and specialty, and access 3,112 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Diamond authentication services worldwide at a glance

As of Nov 6, 2026
22.5%Verified-email coverage
12.2Average contacts per company
1-10Median size (employees)
7.1%Largest-city concentration · New York
Nov 6, 2026Page data refreshed

Companies by employee count

1-10
628
11-50
311
51-200
81
201-500
34
501-1,000
27
1,001-5,000
22
5,001-10,000
1
10001+
3

Email recency is reported on each country list linked below.

How this list was built

The recorded descriptions help you assess these company matches. Check a company’s website for its current services and locations.

Source
The RevenueBase company graph: 60 million companies and 398.9 million professional contacts resolved from primary sources, queried with RevenueBase SmartSearch, the natural-language company search available to every RevenueBase user.
Coverage
Every country. Country and city lists for diamond authentication services are linked below.
What qualifies
Company records worldwide whose business descriptions match “diamond authentication services” by meaning at the Exact setting. Descriptions are compiled in the RevenueBase company graph from public websites, profiles and company information where available; they are not guaranteed quotations from the company's website.
RevenueBase SmartSearch
Describe a niche company in your own words to find businesses by meaning. Exact, Similar, Related and Broad control the breadth of RevenueBase SmartSearch. This saved list uses Exact. Each row's Exact match badge shows inclusion in that search, not an individual score or a service-quality judgment.
Public preview
The public preview omits records without a verified work email. Dataset totals and geographic summaries describe the full matched records before these preview filters.
Match quality
RevenueBase's August 25, 2026 study assessed 4,198 description/company pairs across matching settings. The publisher reports 86% good or better at Exact. This evaluates the method across queries; it does not audit this individual list. Recorded company descriptions, where available, help you judge each match yourself. Read the full methodology: how the lists are built and what the study measures.
Ranking
Team size, largest first: companies are ordered by the number of professionals RevenueBase tracks at each one. Employee ranges shown are reported bands, for context.
Verification
Every displayed company carries at least one verified work email. RevenueBase tracks 3,112 professional contacts with verified work emails across the full matched dataset. Contacts re-verify on a rolling cadence, and each contact's own verification date is shown inside RevenueBase.
Refresh
This page's figures were pulled from the company graph on November 6, 2026. Lists refresh periodically as the graph is re-checked.
Record context
Company records and descriptions can change. Check the company's website for its current services and locations.

Diamond authentication services by location

10 lists · largest first

Every Diamond authentication services list RevenueBase publishes, by country and city. Counts are matching companies in each list as of its own refresh date.

Countries

Cities

Frequently asked

What is RevenueBase SmartSearch?

RevenueBase SmartSearch finds niche companies by the meaning of their business descriptions in the RevenueBase company graph. Exact, Similar, Related and Broad control how closely companies must fit your description. This list uses Exact for “diamond authentication services”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many diamond authentication services are there worldwide?

RevenueBase identified 1,128 company matches for diamond authentication services worldwide as of November 2026, using the meaning of business descriptions at Exact. This is the recorded matched set in the RevenueBase company graph.

What is the largest company on this list?

Blue Nile tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which country has the most diamond authentication services?

The United States leads with 253 companies, followed by India (226) and the United Kingdom (51). Every diamond authentication services list by country and city is linked on this page.

Which city has the most diamond authentication services?

New York leads with 80 company records, followed by Mumbai (65) and Surat (63).

How do I get contact information for these companies?

A free RevenueBase account lets you run this exact search and work limited free results with 500 credits to start. Upgrading provides access to the 3,112 professional contacts with verified work emails tracked across these 1,128 companies; direct dials are available where recorded.

How current is this list?

The list refreshes periodically as the company graph is re-checked. This page's figures were pulled on November 6, 2026.

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About this data

RevenueBase is a B2B data infrastructure company. Its company graph covers 60 million companies and 398.9 million professional contacts, with emails verified on a rolling cadence rather than scraped once and left to decay. These company lists are generated directly from that graph with RevenueBase SmartSearch, the same natural-language company search every RevenueBase user has: describe a market in plain words, get the companies that match, and add verified emails and direct dials for the people at them. It is the same data that powers RevenueBase's B2B data products, and a free account includes 500 credits to start. How these lists are built and judged.