B2B Diamond Intake and Quality Control: Inspection Protocols

Diamond quality inspection requires a controlled, standardized optical environment. Conducting inspections under arbitrary showroom spotlights or warm incandescent lamps distorts color and conceals inclusions. A professional QC bench must be equipped with:

• Calibrated Daylight Lighting: A daylight-equivalent lamp producing 5500K to 6500K color temperature with a Color Rendering Index (CRI) of 95+.
• Stereo Gemological Microscope: 10x to 45x continuous zoom magnification with darkfield, brightfield, and overhead fiber-optic illumination.
• 10x & 20x Achromatic Triplet Loupes: Corrected for spherical and chromatic aberrations.
• Digital Non-Contact or Dial Calipers: Measuring dimensions to +/- 0.01 mm precision.
• High-Precision Carat Scale: Calibrated to 0.001 carats (three decimal places).
• Long-Wave & Short-Wave UV Chamber: For testing fluorescence and phosphorescence signatures.

When a shipment arrives, technicians follow a rigorous sequential protocol:

1. Step 1: Tamper-Evident Seal Inspection: Verify that courier security tape and vendor parcel seals are unbroken. Cross-check airway bill tracking against packing slips.
2. Step 2: Carat Weight Verification: Remove the loose stone and place it on a leveled, calibrated carat scale. The weight must match the certificate within +/- 0.005 carats.
3. Step 3: Dimensional Measurement: Measure maximum diameter, minimum diameter, and total depth with digital calipers. Record readings to two decimal places.
4. Step 4: Girdle Laser Inscription Read: Under 20x magnification, locate and read the microscopic laser inscription on the girdle, verifying exact alphanumeric match with the certificate.
5. Step 5: Face-Up Optical Inspection: Examine the stone face-up under 10x magnification for eye-clean status, verifying that no unmapped inclusions or dark spots affect visual brilliance.

Inspect the stone for subtle cutting or structural defects that could compromise jewelry setting:

For bulk melee parcels (e.g., 50 carats containing over 2,000 stones), testing every stone is impossible. Professional QC teams utilize Statistical Acceptance Sampling (AQL 1.0 Standard):

• Draw a random sample of 50 stones across different depths of the parcel paper.
• Pass the sample through top and bottom calibration sieve plates to verify zero out-of-spec stones.
• Measure 10 individual stones with a digital lever gauge to confirm diameter variance within +/- 0.025 mm.
• Inspect the sample under 10x magnification: 100% of stones must meet the agreed color tier (e.g. D-F) and clarity tier (VVS-VS).

If any non-conforming stone is identified:

1. Immediately place the stone in a red-coded "Quarantine" parcel envelope with a written discrepancy report (e.g., "Carat scale reads 2.01 ct vs 2.04 ct on cert" or "Chip observed on pavilion facet").
2. Capture high-magnification photomicrographs through the microscope eyepiece documenting the defect.
3. Notify the supplier’s account manager within the inspection window (typically within 48 hours of receipt) to initiate exchange or credit memo processing.

At Lavish, our pre-shipment quality audit eliminates these issues before orders depart, delivering pristine, verified inventory directly to your atelier.