Price differences for surveyed diamonds

Table 3. Average cost of all 17 stones based on their grading and the premium or discount^[1] that their certificates attract.

Stone #	GIA-GTL	AGSL		EGL USA
Stone #	Price	Price	Diff. to GIA	Price	Diff. to GIA
1	$2,576	$2,296	-11%	$2,458	-5%
2	$2,922	$2,922	0%	$2,758	-6%
3	$4,248	$4,426	4%	$3,634	-14%
4	$4,540	$4,541	0%	$3,925	-14%
5	$1,522	$1,456	-4%	$1,527	0%
6	$1,496	$1,964	31%	$1,478	-1%
7	$2,075	$1,915	-8%	$1,707	-18%
8	$1,607	$1,501	-7%	$1,569	-2%
9	$2,058	$2,219	8%	$1,696	-18%
10	$2,453			$2,212	-10%
11	$2,952	$2,668	-10%	$2,624	-11%
12	$2,653	$2,398	-10%	$2,103	-21%
13	$2,152	$2,152	0%	$2,137	-1%
14	$4,127	$5,907	43%	$4,716	14%
15	$8,451	$7,264	-14%	$6,739	-20%
16	$8,255	$7,708	-7%	$6,323	-23%
17	$2,246	$2,047	-9%	$1,892	-16%
Average	$3,314	$3,337	1%	$2,912	-10%

Stone #
1
GIA-GTL Price	$2,576
AGSL Price	$2,296
AGSL Diff. to GIA	-11%
EGL USA Price	$2,458
EGL USA Diff. to GIA	-5%
2
GIA-GTL Price	$2,922
AGSL Price	$2,922
AGSL Diff. to GIA	0%
EGL USA Price	$2,758
EGL USA Diff. to GIA	-6%
3
GIA-GTL Price	$4,248
AGSL Price	$4,426
AGSL Diff. to GIA	4%
EGL USA Price	$3,634
EGL USA Diff. to GIA	-14%
4
GIA-GTL Price	$4,540
AGSL Price	$4,541
AGSL Diff. to GIA	0%
EGL USA Price	$3,925
EGL USA Diff. to GIA	-14%
5
GIA-GTL Price	$1,522
AGSL Price	$1,456
AGSL Diff. to GIA	-4%
EGL USA Price	$1,527
EGL USA Diff. to GIA	0%
6
GIA-GTL Price	$1,496
AGSL Price	$1,964
AGSL Diff. to GIA	31%
EGL USA Price	$1,478
EGL USA Diff. to GIA	-1%
7
GIA-GTL Price	$2,075
AGSL Price	$1,915
AGSL Diff. to GIA	-8%
EGL USA Price	$1,707
EGL USA Diff. to GIA	-18%
8
GIA-GTL Price	$1,607
AGSL Price	$1,501
AGSL Diff. to GIA	-7%
EGL USA Price	$1,569
EGL USA Diff. to GIA	-2%
9
GIA-GTL Price	$2,058
AGSL Price	$2,219
AGSL Diff. to GIA	8%
EGL USA Price	$1,696
EGL USA Diff. to GIA	-18%
10
GIA-GTL Price	$2,453
AGSL Price
AGSL Diff. to GIA
EGL USA Price	$2,212
EGL USA Diff. to GIA	-10%
11
GIA-GTL Price	$2,952
AGSL Price	$2,668
AGSL Diff. to GIA	-10%
EGL USA Price	$2,624
EGL USA Diff. to GIA	-11%
12
GIA-GTL Price	$2,653
AGSL Price	$2,398
AGSL Diff. to GIA	-10%
EGL USA Price	$2,103
EGL USA Diff. to GIA	-21%
13
GIA-GTL Price	$2,152
AGSL Price	$2,152
AGSL Diff. to GIA	0%
EGL USA Price	$2,137
EGL USA Diff. to GIA	-1%
14
GIA-GTL Price	$4,127
AGSL Price	$5,907
AGSL Diff. to GIA	43%
EGL USA Price	$4,716
EGL USA Diff. to GIA	14%
15
GIA-GTL Price	$8,451
AGSL Price	$7,264
AGSL Diff. to GIA	-14%
EGL USA Price	$6,739
EGL USA Diff. to GIA	-20%
16
GIA-GTL Price	$8,255
AGSL Price	$7,708
AGSL Diff. to GIA	-7%
EGL USA Price	$6,323
EGL USA Diff. to GIA	-23%
17
GIA-GTL Price	$2,246
AGSL Price	$2,047
AGSL Diff. to GIA	-9%
EGL USA Price	$1,892
EGL USA Diff. to GIA	-16%
Average
GIA-GTL Price	$3,314
AGSL Price	$3,337
AGSL Diff. to GIA	1%
EGL USA Price	$2,912
EGL USA Diff. to GIA	-10%

Figure 3. Price differences compared to similar GIA-GTL graded diamonds. Each positive or negative difference on the chart corresponds to higher or lower prices for similar diamonds listed for sale with respective reports.

Figure 4. 56% of the surveyed diamonds would cost less if sold with AGS rather than GIA reports, mainly as a result of stricter clarity grading 80% of the diamonds would cost less if bought with EGL rather than GIA reports. Discounting of EGL graded diamonds was greater than any premiums as a result of softer color grading.