Company lists · Data refreshed November 2026

Top 25 Gemstone authentication services worldwide

RevenueBase identified 705 company matches for gemstone authentication services worldwide as of November 2026 and tracks 7,255 professional contacts across them, including 1,926 with verified work emails. India is the largest market and Jaipur the largest hub.

This list covers company matches for gemstone 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 gemstone 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
705Companies
7,255Contacts tracked
1,926Verified emails
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The 25 largest gemstone authentication services worldwide

Ranked by team size
Top 25 of 705 company matches for gemstone 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, 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
2Exact 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
3Exact 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
4Exact 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
5Exact matchGurgaon, IndiaHQ recorded Nov 6, 2026201-500127 contacts →

Exact match

“GemPundit is one of the leading providers of Luxury, Precious & Semi-Precious Gemstones.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
6Exact 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
7Exact 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
8Exact matchLondon, United KingdomHQ recorded Nov 6, 202611-5051 contacts →

Exact match

“Creating and supporting gemmologists since 1908.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
9Exact matchRochester, NY, United StatesHQ recorded Nov 6, 202651-20050 contacts →

Exact match

“America's Diamond Specialist - Memo and Stock Quality, attention to detail, honesty, fairness, and on-time delivery.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
10Exact matchManama, BahrainHQ recorded Nov 6, 202611-5048 contacts →

Exact match

“As a reflection of Bahrain’s ancient pearling history and the strong desire to protect this heritage, the Bahrain Institute for Pearls & Gemstones (DANAT) was established as the…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
11Exact matchBasel, SwitzerlandHQ recorded Nov 6, 202611-5029 contacts →

Exact match

“The Swiss Gemmological Institute, part of the Swiss Foundation for the Research of Gemstones (SSEF: Schweizerische Stiftung für Edelstein-Forschung) was founded by trade…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
12Exact matchRozelle, AustraliaHQ recorded Nov 6, 202651-20028 contacts →

Exact match

“The Gemmological Association of Australia (GAA) is Australia’s long established gemmological educator.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
13Exact matchGeneva, SwitzerlandHQ recorded Nov 6, 202611-5026 contacts →

Exact match

“GGTL Laboratories is the merging of two laboratories: GemTechLab, founded in 1996 by Franck Notari in Geneva, Switzerland and GEMLAB (Liechtenstein), founded in 1996 by Thomas…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
14Exact matchBangkok, ThailandHQ recorded Nov 6, 202611-5025 contacts →

Exact match

“ICA | GemLab is an expert in identification, origin determination, and treatment detection for colored gemstones.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
15Exact matchIstanbul, TürkiyeHQ recorded Nov 6, 202651-20024 contacts →

Exact match

“Yolculuğumuz, 10 yılı aşkın süredir yüzbinlerce pırlantayı derecelendiren uzman gemologların bir araya gelmesiyle başladı.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
16Exact matchMumbai, IndiaHQ recorded Nov 6, 202611-5021 contacts →

Exact match

“We specialize in GIA certified diamonds with a choice of 6,500+ stones with AI technology of Auto Answering and 24*7 @Bot helpline to serve all our customers regardless of time…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
17Exact matchLucerne, SwitzerlandHQ recorded Nov 6, 202611-5020 contacts →

Exact match

“The Gübelin Gem Lab was founded in 1923 as a small gemmological laboratory to examine and determine the authenticity of the stones used in Gübelin’s jewellery.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
18Exact matchBangkok, ThailandHQ recorded Nov 6, 202611-5020 contacts →

Exact match

“The Asian Institute of Gemological Sciences (AIGS) was founded in 1978 as South East Asia’s first international gemological education facility.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
19Exact matchUnited StatesHQ recorded Nov 6, 202611-5019 contacts →

Exact match

“Um ecossistema 360º de serviços especializados para o mercado de joias, gemas e metais preciosos.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
20Exact matchParis, FranceHQ recorded Nov 6, 202611-5017 contacts →

Exact match

“Maison PIAT specializes in the search and cut of natural colored and non-treated gemstones.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
21Exact matchNew York, NY, United StatesHQ recorded Nov 6, 202611-5017 contacts →

Exact match

“Founded in 2015, Ritzin is the global leader in ethically sourced in the Gems and jewelry Industry.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
22Exact matchCharlotte, NC, United StatesHQ recorded Nov 6, 202611-5013 contacts →

Exact match

“We have built our business around a fully-equipped diamond grading laboratory.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
23Exact matchJammu, IndiaHQ recorded Nov 6, 20261-1013 contacts →

Exact match

“Pramogh is a leading brand offering natural, certified gemstones sourced from trusted mines across the world.”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
24Exact matchVancouver, CanadaHQ recorded Nov 6, 202651-20013 contacts →

Exact match

“LegitApp - The World's Leading Luxury Authentication * Featured in ELLE, Harper's BAZAAR, Hypebeast, TikTok Shop and More** LegitApp is the world's leading authentication solution…”

Recorded in the RevenueBase company graph · Nov 6, 2026 · View company records in RevenueBase
25Exact matchNew York, NY, United StatesHQ recorded Nov 6, 202611-5012 contacts →

Exact match

Recorded description not available.

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

Showing 25 of 705 gemstone authentication services worldwide

See the full list, filter by size, metro and specialty, and access 1,926 tracked professional contacts with verified work emails. Direct dials are available where recorded.

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Gemstone authentication services worldwide at a glance

As of Nov 6, 2026
26.5%Verified-email coverage
10.3Average contacts per company
1-10Median size (employees)
5.7%Largest-city concentration · Jaipur
Nov 6, 2026Page data refreshed

Companies by employee count

1-10
468
11-50
160
51-200
47
201-500
12
501-1,000
9
1,001-5,000
3
5,001-10,000
1

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 gemstone authentication services are linked below.
What qualifies
Company records worldwide whose business descriptions match “gemstone 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 1,926 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.

Gemstone authentication services by location

3 lists · largest first

Every Gemstone 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 “gemstone authentication services”; each Exact match badge shows search membership, not an individual similarity or quality score.

How many gemstone authentication services are there worldwide?

RevenueBase identified 705 company matches for gemstone 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?

International Gemological Institute - USA tops the displayed preview by professional contacts tracked in RevenueBase. Recorded headquarters appear in the company rows.

Which country has the most gemstone authentication services?

India leads with 138 companies, followed by the United States (116). Every gemstone authentication services list by country and city is linked on this page.

Which city has the most gemstone authentication services?

Jaipur leads with 40 company records, followed by New York (27) and Bangkok (17).

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 1,926 professional contacts with verified work emails tracked across these 705 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.