Koustav Gemological Laboratory ISO 9001:2015
DL Roy Rd, Near Krishnagar Municipality, Krishnagar
ISO 9001:2015 Certified Gemological Testing Center
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Get in Touch with Our Laboratory

Have questions about gemstone testing rates, specimen submissions, or certificate verification? Our certified team is here to assist you.

Direct Call

Speak directly with our gem testing helpdesk.

+91 7548016604
WhatsApp Chat

Instant messaging for quick report inquiries.

Chat on WhatsApp
Email Inquiries

Send official inquiries & corporate requests.

info@koustav.com
Service Request

Send Your Testing Inquiry

Fill out the form below and our certified gemologists will review your query promptly.

Diamond Grading Ruby & Sapphire Emerald & Beryl Pearl & Rudraksha Certificate Verification
All diagnostic inquiries are treated with strict confidentiality under ISO 9001:2015 standards.
Laboratory Operating
Schedule
Open Today
  • Monday – Friday: 11:00 AM – 6:30 PM
  • Saturday: 11:00 AM – 5:00 PM
  • Sunday: Closed
Specimen Drop-off Protocol

Clients visiting our Krishnagar laboratory in person receive an official intake acknowledgment slip noting initial weight and optical baseline before testing begins.

Laboratory Location
Open in Google Maps
DL Roy Rd, Near Krishnagar Municipality Get Directions →
Common Questions

Frequently Asked Questions Regarding Contact & Testing

Our diagnostic desk reviews incoming messages continuously during operational hours (Monday – Saturday). You will typically receive a phone or WhatsApp callback within 2 to 4 business hours.

Yes, walk-in submissions are accepted at our DL Roy Road facility in Krishnagar during regular hours. For express testing or bulk diamond parcels, we recommend calling ahead at +91 7548016604.

You can instantly verify certificates by visiting our Certificate Verification portal and entering your unique Report Number or scanning the QR code printed on the physical card.