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Overview

When there is an extra facet adjacent to the girdle, GIA and Octonus use different methods to handle them, which defines different shapes of the corresponding girdle curve. Later, the points related to the calculation of the stone heights will be searched on this curve.

Currently, the GIA method is used in the system. Octonus values for Girdle bezel, Girdle bone, and Girdle valley are also calculated for testing purposes, but available only via Export Report Data function.

Girdle heights calculation method
GIA method	Octonus method

Notes facet adjacent to the girdle (from any side) with height more than 10° from Total Height is not a girdle facet and never affects girdle height calculation steep girdle extra facet has less than 15° deviation from the girdle plane shallow girdle extra facet - more than 15° a virtual model is built by removing the extra facets and the neighboring facets are continued until they intersect
Steep extra girdle facets are calculated as a part of a girdle. Uses real model and excludes Shallow extra girdle facets during girdle heights calculation.	Steep extra girdle facets are calculated as a part of a girdle. Uses virtual model built on the real brilliant model but without Shallow extra girdle facets.

The following parameters are calculated differently:

For these parameters, the normal bookmark set is extended with the same bookmarks with _GIA and _OCT in their names.

This functionality is currently available only under the following HASP keys:

"Developer" HASP key
7-30542
7-30546

For example,

GIRDLE_WIDE_BEZEL_MAX
GIRDLE_WIDE_BEZEL_6
GIRDLE_WIDE_BEZEL_MAX_GIA
GIRDLE_WIDE_BEZEL_6_GIA
GIRDLE_WIDE_BEZEL_MAX_OCT
GIRDLE_WIDE_BEZEL_6_OCT

Currently, for girdle heights calculation, the GIA method is used, which means all reports and appraisers contain GIA method results.

Therefore, values of default bookmarks are equal to _GIA, that is, for example, GIRDLE_WIDE_BEZEL_MAX = GIRDLE_WIDE_BEZEL_MAX_GIA

Examples

Girdle Bezel Difference Example

Here is an example of how Girdle Bezel is calculated differently using GIA and Octonus methods.

Project File with models for this sample	2005_01_28_kb7 (4).oxgz

See details on how points are found in the "Finding Points" section of the Stone Heights Calculation page.

Show All Bookmarks-Values

GIRDLE_WIDE_BEZEL_1_OCT	2.87	GIRDLE_WIDE_BEZEL_1_GIA	2.87	GIRDLE_WIDE_BEZEL_MM_1_OCT	0.137	GIRDLE_WIDE_BEZEL_MM_1_GIA	0.137
GIRDLE_WIDE_BEZEL_2_OCT	2.5	GIRDLE_WIDE_BEZEL_2_GIA	2.22	GIRDLE_WIDE_BEZEL_MM_2_OCT	0.119	GIRDLE_WIDE_BEZEL_MM_2_GIA	0.106
GIRDLE_WIDE_BEZEL_3_OCT	3.35	GIRDLE_WIDE_BEZEL_3_GIA	3.35	GIRDLE_WIDE_BEZEL_MM_3_OCT	0.16	GIRDLE_WIDE_BEZEL_MM_3_GIA	0.16
GIRDLE_WIDE_BEZEL_4_OCT	3.21	GIRDLE_WIDE_BEZEL_4_GIA	3.21	GIRDLE_WIDE_BEZEL_MM_4_OCT	0.153	GIRDLE_WIDE_BEZEL_MM_4_GIA	0.153
GIRDLE_WIDE_BEZEL_5_OCT	2.66	GIRDLE_WIDE_BEZEL_5_GIA	2.66	GIRDLE_WIDE_BEZEL_MM_5_OCT	0.127	GIRDLE_WIDE_BEZEL_MM_5_GIA	0.127
GIRDLE_WIDE_BEZEL_6_OCT	2.58	GIRDLE_WIDE_BEZEL_6_GIA	2.58	GIRDLE_WIDE_BEZEL_MM_6_OCT	0.123	GIRDLE_WIDE_BEZEL_MM_6_GIA	0.123
GIRDLE_WIDE_BEZEL_7_OCT	2.64	GIRDLE_WIDE_BEZEL_7_GIA	2.64	GIRDLE_WIDE_BEZEL_MM_7_OCT	0.126	GIRDLE_WIDE_BEZEL_MM_7_GIA	0.126
GIRDLE_WIDE_BEZEL_8_OCT	2.99	GIRDLE_WIDE_BEZEL_8_GIA	2.99	GIRDLE_WIDE_BEZEL_MM_8_OCT	0.143	GIRDLE_WIDE_BEZEL_MM_8_GIA	0.143
GIRDLE_WIDE_BEZEL_MIN_OCT	2.5	GIRDLE_WIDE_BEZEL_MIN_GIA	2.22	GIRDLE_WIDE_BEZEL_MM_MIN_OCT	0.119	GIRDLE_WIDE_BEZEL_MM_MIN_GIA	0.106
GIRDLE_WIDE_BEZEL_MAX_OCT	3.35	GIRDLE_WIDE_BEZEL_MAX_GIA	3.35	GIRDLE_WIDE_BEZEL_MM_MAX_OCT	0.16	GIRDLE_WIDE_BEZEL_MM_MAX_GIA	0.16
GIRDLE_WIDE_BEZEL_AVG_OCT	2.85	GIRDLE_WIDE_BEZEL_AVG_GIA	2.81	GIRDLE_WIDE_BEZEL_MM_AVG_OCT	0.136	GIRDLE_WIDE_BEZEL_MM_AVG_GIA	0.134
GIRDLE_WIDE_BEZEL_DEV_OCT	0.85	GIRDLE_WIDE_BEZEL_DEV_GIA	1.13	GIRDLE_WIDE_BEZEL_MM_DEV_OCT	0.041	GIRDLE_WIDE_BEZEL_MM_DEV_GIA	0.054

Girdle Bezel values summary:

		OCT,%	GIA,%	OCT,mm	GIA,mm
GIRDLE_WIDE_BEZEL	1	2.87	2.87	0.137	0.137
	2	2.5	2.22	0.119	0.106
	3	3.35	3.35	0.16	0.16
	4	3.21	3.21	0.153	0.153
	5	2.66	2.66	0.127	0.127
	6	2.58	2.58	0.123	0.123
	7	2.64	2.64	0.126	0.126
	8	2.99	2.99	0.143	0.143
	MIN	2.5	2.22	0.119	0.106
	MAX	3.35	3.35	0.16	0.16
	AVG	2.85	2.81	0.136	0.134
	DEV	0.85	1.13	0.041	0.054

Girdle Bone Difference Example

Here is an example of how Girdle Bone is calculated differently using GIA and Octonus methods.

Project File with models for this sample	2005_01_28_kb7 (4).oxgz

See details on how points are found in the "Finding Points" section of the Stone Heights Calculation page.

Show All Bookmarks-Values

GIRDLE_WIDE_BONE_1_OCT	3.27	GIRDLE_WIDE_BONE_1_GIA	3.27	GIRDLE_WIDE_BONE_MM_1_OCT	0.156	GIRDLE_WIDE_BONE_MM_1_GIA	0.156
GIRDLE_WIDE_BONE_2_OCT	3.57	GIRDLE_WIDE_BONE_2_GIA	3.57	GIRDLE_WIDE_BONE_MM_2_OCT	0.17	GIRDLE_WIDE_BONE_MM_2_GIA	0.17
GIRDLE_WIDE_BONE_3_OCT	3.68	GIRDLE_WIDE_BONE_3_GIA	3.68	GIRDLE_WIDE_BONE_MM_3_OCT	0.176	GIRDLE_WIDE_BONE_MM_3_GIA	0.176
GIRDLE_WIDE_BONE_4_OCT	3.28	GIRDLE_WIDE_BONE_4_GIA	3.28	GIRDLE_WIDE_BONE_MM_4_OCT	0.157	GIRDLE_WIDE_BONE_MM_4_GIA	0.157
GIRDLE_WIDE_BONE_5_OCT	3.84	GIRDLE_WIDE_BONE_5_GIA	3.84	GIRDLE_WIDE_BONE_MM_5_OCT	0.183	GIRDLE_WIDE_BONE_MM_5_GIA	0.183
GIRDLE_WIDE_BONE_6_OCT	3.19	GIRDLE_WIDE_BONE_6_GIA	2.7	GIRDLE_WIDE_BONE_MM_6_OCT	0.153	GIRDLE_WIDE_BONE_MM_6_GIA	0.129
GIRDLE_WIDE_BONE_7_OCT	3.54	GIRDLE_WIDE_BONE_7_GIA	3.54	GIRDLE_WIDE_BONE_MM_7_OCT	0.169	GIRDLE_WIDE_BONE_MM_7_GIA	0.169
GIRDLE_WIDE_BONE_8_OCT	3.29	GIRDLE_WIDE_BONE_8_GIA	3.29	GIRDLE_WIDE_BONE_MM_8_OCT	0.157	GIRDLE_WIDE_BONE_MM_8_GIA	0.157
GIRDLE_WIDE_BONE_MIN_OCT	3.19	GIRDLE_WIDE_BONE_MIN_GIA	2.7	GIRDLE_WIDE_BONE_MM_MIN_OCT	0.153	GIRDLE_WIDE_BONE_MM_MIN_GIA	0.129
GIRDLE_WIDE_BONE_MAX_OCT	3.84	GIRDLE_WIDE_BONE_MAX_GIA	3.84	GIRDLE_WIDE_BONE_MM_MAX_OCT	0.183	GIRDLE_WIDE_BONE_MM_MAX_GIA	0.183
GIRDLE_WIDE_BONE_AVG_OCT	3.46	GIRDLE_WIDE_BONE_AVG_GIA	3.4	GIRDLE_WIDE_BONE_MM_AVG_OCT	0.165	GIRDLE_WIDE_BONE_MM_AVG_GIA	0.162
GIRDLE_WIDE_BONE_DEV_OCT	0.65	GIRDLE_WIDE_BONE_DEV_GIA	1.13	GIRDLE_WIDE_BONE_MM_DEV_OCT	0.031	GIRDLE_WIDE_BONE_MM_DEV_GIA	0.054

Girdle Bezel values summary:

		OCT,%	GIA,%	OCT,mm	GIA,mm
GIRDLE_WIDE_BONE	1	3.27	3.27	0.156	0.156
	2	3.57	3.57	0.17	0.17
	3	3.68	3.68	0.176	0.176
	4	3.28	3.28	0.157	0.157
	5	3.84	3.84	0.183	0.183
	6	3.19	2.7	0.153	0.129
	7	3.54	3.54	0.169	0.169
	8	3.29	3.29	0.157	0.157
	MIN	3.19	2.7	0.153	0.129
	MAX	3.84	3.84	0.183	0.183
	AVG	3.46	3.4	0.165	0.162
	DEV	0.65	1.13	0.031	0.054

Girdle Valley Difference Example

Here is an example of how Girdle Valley is calculated differently using GIA and Octonus methods.

Project File with models for this sample	Valley - Combined.oxgz

See details on how points are found in the "Finding Points" section of the Stone Heights Calculation page.

Show All Bookmarks-Values

GIRDLE_NARROW_1_OCT	3.66	GIRDLE_NARROW_1_GIA	3.66	GIRDLE_NARROW_MM_1_OCT	0.169	GIRDLE_NARROW_MM_1_GIA	0.169
GIRDLE_NARROW_2_OCT	3.72	GIRDLE_NARROW_2_GIA	3.72	GIRDLE_NARROW_MM_2_OCT	0.172	GIRDLE_NARROW_MM_2_GIA	0.172
GIRDLE_NARROW_3_OCT	4.04	GIRDLE_NARROW_3_GIA	3.88	GIRDLE_NARROW_MM_3_OCT	0.187	GIRDLE_NARROW_MM_3_GIA	0.18
GIRDLE_NARROW_4_OCT	3.92	GIRDLE_NARROW_4_GIA	4.6	GIRDLE_NARROW_MM_4_OCT	0.181	GIRDLE_NARROW_MM_4_GIA	0.213
GIRDLE_NARROW_5_OCT	4.01	GIRDLE_NARROW_5_GIA	4.01	GIRDLE_NARROW_MM_5_OCT	0.186	GIRDLE_NARROW_MM_5_GIA	0.186
GIRDLE_NARROW_6_OCT	3.94	GIRDLE_NARROW_6_GIA	3.94	GIRDLE_NARROW_MM_6_OCT	0.182	GIRDLE_NARROW_MM_6_GIA	0.182
GIRDLE_NARROW_7_OCT	2.91	GIRDLE_NARROW_7_GIA	2.91	GIRDLE_NARROW_MM_7_OCT	0.135	GIRDLE_NARROW_MM_7_GIA	0.135
GIRDLE_NARROW_8_OCT	2.5	GIRDLE_NARROW_8_GIA	2.5	GIRDLE_NARROW_MM_8_OCT	0.115	GIRDLE_NARROW_MM_8_GIA	0.115
GIRDLE_NARROW_9_OCT	2.68	GIRDLE_NARROW_9_GIA	2.68	GIRDLE_NARROW_MM_9_OCT	0.124	GIRDLE_NARROW_MM_9_GIA	0.124
GIRDLE_NARROW_10_OCT	2.28	GIRDLE_NARROW_10_GIA	2.28	GIRDLE_NARROW_MM_10_OCT	0.105	GIRDLE_NARROW_MM_10_GIA	0.105
GIRDLE_NARROW_11_OCT	2.17	GIRDLE_NARROW_11_GIA	2.17	GIRDLE_NARROW_MM_11_OCT	0.1	GIRDLE_NARROW_MM_11_GIA	0.1
GIRDLE_NARROW_12_OCT	3.09	GIRDLE_NARROW_12_GIA	3.09	GIRDLE_NARROW_MM_12_OCT	0.143	GIRDLE_NARROW_MM_12_GIA	0.143
GIRDLE_NARROW_13_OCT	3.57	GIRDLE_NARROW_13_GIA	3.57	GIRDLE_NARROW_MM_13_OCT	0.165	GIRDLE_NARROW_MM_13_GIA	0.165
GIRDLE_NARROW_14_OCT	3.45	GIRDLE_NARROW_14_GIA	3.45	GIRDLE_NARROW_MM_14_OCT	0.159	GIRDLE_NARROW_MM_14_GIA	0.159
GIRDLE_NARROW_15_OCT	2.94	GIRDLE_NARROW_15_GIA	2.54	GIRDLE_NARROW_MM_15_OCT	0.136	GIRDLE_NARROW_MM_15_GIA	0.118
GIRDLE_NARROW_16_OCT	3.23	GIRDLE_NARROW_16_GIA	2.09	GIRDLE_NARROW_MM_16_OCT	0.15	GIRDLE_NARROW_MM_16_GIA	0.097
GIRDLE_NARROW_MIN_OCT	2.17	GIRDLE_NARROW_MIN_GIA	2.09	GIRDLE_NARROW_MM_MIN_OCT	0.1	GIRDLE_NARROW_MM_MIN_GIA	0.097
GIRDLE_NARROW_MAX_OCT	4.04	GIRDLE_NARROW_MAX_GIA	4.6	GIRDLE_NARROW_MM_MAX_OCT	0.187	GIRDLE_NARROW_MM_MAX_GIA	0.213
GIRDLE_NARROW_AVG_OCT	3.26	GIRDLE_NARROW_AVG_GIA	3.19	GIRDLE_NARROW_MM_AVG_OCT	0.151	GIRDLE_NARROW_MM_AVG_GIA	0.148
GIRDLE_NARROW_DEV_OCT	1.87	GIRDLE_NARROW_DEV_GIA	2.51	GIRDLE_NARROW_MM_DEV_OCT	0.087	GIRDLE_NARROW_MM_DEV_GIA	0.116

Girdle Bezel values summary:

		OCT,%	GIA,%	OCT,mm	GIA,mm
GIRDLE_NARROW	1	3.66	3.66	0.169	0.169
	2	3.72	3.72	0.172	0.172
	3	4.04	3.88	0.187	0.18
	4	3.92	4.6	0.181	0.213
	5	4.01	4.01	0.186	0.186
	6	3.94	3.94	0.182	0.182
	7	2.91	2.91	0.135	0.135
	8	2.5	2.5	0.115	0.115
	9	2.68	2.68	0.124	0.124
	10	2.28	2.28	0.105	0.105
	11	2.17	2.17	0.1	0.1
	12	3.09	3.09	0.143	0.143
	13	3.57	3.57	0.165	0.165
	14	3.45	3.45	0.159	0.159
	15	2.94	2.54	0.136	0.118
	16	3.23	2.09	0.15	0.097
	MIN	2.17	2.09	0.1	0.097
	MAX	4.04	4.6	0.187	0.213
	AVG	3.26	3.19	0.151	0.148
	DEV	1.87	2.51	0.087	0.116

Related Pages

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Stone Heights Calculation
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Girdle Heights Calculation Methods

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Overview

Examples

Girdle Bezel Difference Example

Girdle Bone Difference Example

Girdle Valley Difference Example

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GIA vs Octonus Girdle Heights Calculation

Overview

Examples

Girdle Bezel Difference Example

Girdle Bone Difference Example

Girdle Valley Difference Example

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