ISO 6893:2024

International
Standard
ISO 6893
First edition
Jewellery and precious metals —
2024-04
Inspection of batches of small
diamonds — Terminology,
classification and test methods
Joaillerie, bijouterie et métaux précieux — Contrôle des lots
de petits diamants — Terminologie, classification et méthodes
d’examen
Reference number
© ISO 2024
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Published in Switzerland
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Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 General . 3
4.1 Batch specifications and characteristics .3
4.2 Inspection .3
5 Authentication . 4
6 Sieving . 4
6.1 General .4
6.2 Estimating the total mass of a small diamond batch by sieving and counting .4
6.3 Estimating a batch size by sieving and weighing .4
6.4 Sieving small diamonds .4
6.4.1 Method . .4
6.4.2 Using sieving plates in a correct order .5
6.4.3 Maximum size of a sieved batch .5
6.4.4 Preventing damages of sieved diamonds .5
6.4.5 Regular control of sieve plates accuracy .6
7 Mass of a batch . 6
7.1 Testing .6
7.2 Expression of the weighed mass of a batch .6
8 Measurements . 6
8.1 Measuring small diamonds .6
8.2 Traditional measurements of single small diamonds .6
8.3 Measuring a small diamond with a profile projector .6
8.4 Measuring automatically dimensions of small diamonds in batch .7
8.5 Description of dimension for a batch . .7
9 Batch size . 7
9.1 Testing .7
9.2 Estimation .7
9.2.1 Estimation by sampling . .7
9.2.2 Estimation using mass and diameter.8
9.3 Description .8
10 Sampling . 8
10.1 Inspecting a batch by sampling .8
10.1.1 General conditions .8
10.1.2 Drawing diamond samples from a batch .8
10.2 Sampling plans for the inspection of a batch of small diamonds .9
10.3 Inspection plan and multiple criteria .9
11 Cut . 9
11.1 Description of cut in a homogenous batch .9
11.2 Description of cut in an inhomogenous batch .9
11.3 Shape .9
11.4 Proportions.9
11.4.1 Testing the proportions of small diamonds .9
11.4.2 Description of proportion grades .10
11.5 Polish .10
11.5.1 Testing the polish of small diamonds .10
11.5.2 Polish grades .10

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11.6 Symmetry .11
11.6.1 Testing the symmetry of small diamonds .11
11.6.2 Symmetry grades .11
12 Colour .11
12.1 Testing the colour of small diamonds .11
12.2 Colour grades .11
13 Fluorescence .12
13.1 Testing the fluorescence of small diamonds . 12
13.1.1 Testing the fluorescence by visual means . 12
13.1.2 Testing the fluorescence by spectrometry. 13
13.2 Description of the fluorescence . 13
14 Clarity .13
14.1 Testing the clarity of small diamonds . 13
14.2 Clarity grades . 13
15 Content of a test report . 14
Annex A (informative) Corresponding figures for round brilliant cut .16
Annex B (informative) Flowchart for «sampling control» .18
Bibliography .21

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