IDEX Price Report for September: Prices Remain Under Pressure

(IDEX Online) - The overall trend remained downward in September, with price decreases again outnumbering increases in both rounds and fancies. Rounds showed broader weakness, particularly among goods from 0.70-cts to 1.99-cts, while fancies were more mixed but also recorded significant downward movement in several larger categories.

Activity was limited in a number of smaller size categories, but became more pronounced from 1.00-cts upwards. There were pockets of positive movement among larger goods, particularly in selected middle and lower colors, but these were not enough to reverse the overall negative direction.

Rounds

Price drops dominated among rounds. There was very little movement in 0.30-cts to 0.39-cts, and only limited activity in 0.23-cts to 0.69-cts. Weakness became more evident from 0.70-cts, with declines concentrated among higher colors and clarities.

The downward trend continued through 1.00-cts to 1.99-cts. The 1.50-cts to 1.99-cts category was particularly one-sided, with substantially more decreases than increases.

Larger rounds showed more two-way movement. In 2.00-cts to 2.99-cts there was a relatively even mix of increases and decreases, while 3.00-cts to 3.99-cts was also mixed. Price drops again dominated in 4.00-cts to 4.99-cts. The 5.00-cts to 5.99-cts category saw a number of increases among lower colors and clarities, although decreases remained more numerous overall.

Fancies

Fancies showed more mixed activity than rounds. The smallest goods recorded numerous increases, particularly among lower colors and clarities, although percentage movements in these low-price categories can appear large because of the small underlying price points.   There was clearer weakness in 0.70-cts to 0.89-cts and again from 1.00-cts upwards. The strongest concentration of declines was in 1.50-cts to 1.99-cts, where decreases overwhelmingly dominated.

Above 2.00-cts the picture was mixed. The 2.00-cts to 2.99-cts and 3.00-cts to 3.99-cts categories contained meaningful activity in both directions. Decreases outnumbered increases in 4.00-cts to 4.99-cts and were more pronounced in 5.00-cts to 5.99-cts.

Rounds

0.18-0.22 ct. E / VS1-VS2 -3.5-4.0%, F / VS1 -4.0%, G-H / I1 -9.0-18.0%

0.23-0.29 ct. F / VS2 -4.0%, I / VS1 -5.0%, K / VVS1 -5.5%

0.30-0.39 ct. No significant movement

0.40-0.44 ct. E / SI1 -3.0%, F / VS2 -2.5%

0.45-0.49 ct. D / IF -3.5%, K / VS2 +4.0%, M-N / VVS2 +4.0-4.5%

0.50-0.69 ct. D / IF-VVS1 -3.5-6.0%, K / SI1 -3.5%, M / VVS1 -3.5%

0.70-0.79 ct. D-F / IF-VVS1 predominantly -4.0-6.5%, M-N / VVS1 -3.5-6.5%

0.80-0.89 ct. D / VVS1-VS1 -4.5-5.5%, F / IF-VVS1 -5.5-6.0%

0.90-0.99 ct. D-F / IF-VVS2 predominantly -3.5-6.5%, K / I2 +9.0%

1.00-1.24 ct. D / VVS2-VS2 -5.5-6.5%, E-F / higher clarities predominantly lower, F / IF +5.5%

1.25-1.49 ct. D / VVS1 -3.5%, G / VS2 +5.0%, I / I2 -5.0%, N / I1 +5.5%

1.50-1.99 ct. D-I / higher clarities predominantly lower, I / VVS1-VVS2 -4.5-5.0%

2.00-2.99 ct. Mixed activity; I / I1 -6.5%, I / VVS1 +4.0%, J / VS2 +5.5%, L / I2 +5.5%

3.00-3.99 ct. Mixed activity; F / SI3 -5.0%, J / SI3 +3.0%, K / SI3 +5.0%, M / SI2 +4.0%

4.00-4.99 ct. Decreases dominated; H / VS2 +4.5%, K / SI3 +5.0%, M / VS2 -4.0%

5.00-5.99 ct. Mixed activity; K / I1 +8.0%, M-N / SI1-SI3 +5.0-8.5%

Fancy Cuts

0.18-0.22 ct. Lower colors and clarities predominantly higher; M-N / SI1-SI3 +20.0-50.0%

0.23-0.29 ct. Increases only; H / I1-I2 +11.0-12.5%, J / I1 +14.5%, K-N / selected I grades +15.0-33.5%

0.30-0.39 ct. G-I / I1-I3 predominantly -9.0-12.5%, M-N / I1 +16.5-20.0%

0.40-0.44 ct. E / I2-I3 +6.0-8.5%, G / I1-I2 -6.0-8.0%, J / I1 +7.5%

0.45-0.49 ct. G / I2 -7.0%, J / I2 +9.0%, L / I1 +9.0%, M / I1 -10.0%

0.50-0.69 ct. D / IF -6.0%, M / SI2-SI3 -6.0%

0.70-0.79 ct. D-F / VS1-VS2 predominantly -5.0-7.0%, H / I3 +6.0%

0.80-0.89 ct. D-G / higher clarities predominantly -3.0-6.0%, E / VS1-VS2 -5.5-6.0%

0.90-0.99 ct. Very little movement; D / IF -3.5%, G / I2 +6.0%

1.00-1.24 ct. D-F / higher clarities predominantly -3.0-6.0%, K / I2 +8.5%, N / SI1-SI2 +7.0-8.5%

1.25-1.49 ct. Mixed activity; F-G / SI1 +5.5-6.0%, I / IF -5.0%, N / SI1-SI2 +6.0-7.0%

1.50-1.99 ct. Decreases dominated; D-I / SI grades broadly lower, G-H / SI2 -7.0%

2.00-2.99 ct. Mixed activity; D / SI2 -3.5%, E / VS1 -4.0%, H-I / selected VVS goods +3.0-3.5%

3.00-3.99 ct. Mixed activity; F / SI1 -4.5%, K / SI3-I2 +5.0%, L-M / VVS1 -6.0-7.0%

4.00-4.99 ct. F / VVS2-VS1 -3.5-4.0%, G / SI1 -3.0%, K / SI3 +6.0%

5.00-5.99 ct. Decreases dominated; H / VS1 +4.5%, H / SI2-SI3 -5.0%, K / SI3 +6.0%, L-N / I3 -6.0-7.0%

Basis of comparison: IDEX Diamond Price Reports dated 01-August-2026 and 01-September-2026. Percentages shown are month-on-month changes in the published asking-price tables.