Jáchymov
West Bohemia, Ore Mountains, Czechia
UraniumU, Ag, Co, Ni, Bi
- Type
- Perigranitic polymetallic uraninite veins (IAEA class 2.2)
Uranium ore sample from the Queen's University collection analysed by Voinot et al. (2024) for U, Mo and Tl; ε205Tl and δ238U decrease together in metamorphic and unconformity deposits (U reduction and Tl redox change), whereas δ97Mo is strongly modified by late remobilisation. Historical vein district of the Ore Mountains (veins up to 2 m along major faults, age of 451 Ma used in the study); δ238U close to the continental crust, δ97Mo of +0.8 to +1.3 ‰ and ε205Tl of -4.0 to -3.4, clearly lighter than the crust. Indicative coordinates (Jáchymov). Uvarova et al. (2014): δ238U (normalisation offset by about +0.60 ‰) and δ234U of samples from the Queen's University collection (Table 2).
δ238U in ‰ (per mil) Values of the same system
Standard : NBL CRM 112-A
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| −0.15 ‰ | 1 | pristine uraninite Single analysis; per-sample uncertainty not published; sample M19330; IAEA class 2.2 Perigranitic (granite-related); average age used 451 Ma; 64.91 % U, 3.63 µg/g Tl, 35.27 µg/g Mo. | Voinot et al. (2024), Tl, Mo and U isotopes in U-ore deposits record Earth's fundamental … | |
| −0.2 ‰ | 1 | uraninite Single analysis; per-sample uncertainty not published; full-procedure duplicate at -0.17; sample M9176A; IAEA class 2.2 Perigranitic (granite-related); average age used 451 Ma; 87.56 % U, 35.32 µg/g Tl, 63.52 µg/g Mo. | Voinot et al. (2024), Tl, Mo and U isotopes in U-ore deposits record Earth's fundamental … | |
| 0.45 ± 0.1 ‰ | 1 | uraninite Single analysis; ± 0.10 ‰ (2 SD, reproducibility); sample M19330, Jáchymov; bracketing-only δ238U at +0.43; 238U/235U of 137.899; about -0.15 ‰ after removing the 0.60 ‰ offset specific to this study; same sample as Voinot et al. (2024), published at -0.15 ‰. | Uvarova et al. (2014), Variations in the uranium isotopic compositions of uranium ores fr… | |
| 0.6 ± 0.1 ‰ | 1 | uraninite Single analysis; ± 0.10 ‰ (2 SD, reproducibility); sample M14887, Jáchymov; bracketing-only δ238U at +0.48; 238U/235U of 137.919; about 0.00 ‰ after removing the 0.60 ‰ offset specific to this study. | Uvarova et al. (2014), Variations in the uranium isotopic compositions of uranium ores fr… | |
| 0.63 ± 0.1 ‰ | 1 | uraninite Single analysis; ± 0.10 ‰ (2 SD, reproducibility); sample M9176B, Jáchymov; bracketing-only δ238U at +0.50; 238U/235U of 137.924; about +0.03 ‰ after removing the 0.60 ‰ offset specific to this study. | Uvarova et al. (2014), Variations in the uranium isotopic compositions of uranium ores fr… | |
| 0.47 ± 0.1 ‰ | 1 | uraninite Single analysis; ± 0.10 ‰ (2 SD, reproducibility); sample M12106, Jáchymov; bracketing-only δ238U at +0.31; 238U/235U of 137.901; about -0.13 ‰ after removing the 0.60 ‰ offset specific to this study. | Uvarova et al. (2014), Variations in the uranium isotopic compositions of uranium ores fr… | |
| 0.41 ± 0.1 ‰ | 1 | uraninite Single analysis; ± 0.10 ‰ (2 SD, reproducibility); sample M9176A, Jáchymov; bracketing-only δ238U at +0.35; 238U/235U of 137.893; about -0.19 ‰ after removing the 0.60 ‰ offset specific to this study; same sample as Voinot et al. (2024), published at -0.20 ‰. | Uvarova et al. (2014), Variations in the uranium isotopic compositions of uranium ores fr… |
δ234U in ‰ (per mil) Values of the same system
Standard : équilibre séculaire
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 0.82 ‰ | 1 | pristine uraninite Single analysis; per-sample uncertainty not published; sample M19330; IAEA class 2.2 Perigranitic (granite-related); average age used 451 Ma; 64.91 % U, 3.63 µg/g Tl, 35.27 µg/g Mo. | Voinot et al. (2024), Tl, Mo and U isotopes in U-ore deposits record Earth's fundamental … | |
| −1 ‰ | 1 | uraninite Single analysis; per-sample uncertainty not published; full-procedure duplicate at +3.0; sample M9176A; IAEA class 2.2 Perigranitic (granite-related); average age used 451 Ma; 87.56 % U, 35.32 µg/g Tl, 63.52 µg/g Mo. | Voinot et al. (2024), Tl, Mo and U isotopes in U-ore deposits record Earth's fundamental … | |
| 3 ‰ | 1 | uraninite Single analysis; per-sample uncertainty not published; sample M19330, Jáchymov; Voinot et al. (2024) report +0.82 ‰ on the same sample. | Uvarova et al. (2014), Variations in the uranium isotopic compositions of uranium ores fr… | |
| 1 ‰ | 1 | uraninite Single analysis; per-sample uncertainty not published; sample M14887, Jáchymov. | Uvarova et al. (2014), Variations in the uranium isotopic compositions of uranium ores fr… | |
| 2 ‰ | 1 | uraninite Single analysis; per-sample uncertainty not published; sample M9176B, Jáchymov. | Uvarova et al. (2014), Variations in the uranium isotopic compositions of uranium ores fr… | |
| 3 ‰ | 1 | uraninite Single analysis; per-sample uncertainty not published; sample M12106, Jáchymov. | Uvarova et al. (2014), Variations in the uranium isotopic compositions of uranium ores fr… | |
| 1 ‰ | 1 | uraninite Single analysis; per-sample uncertainty not published; sample M9176A, Jáchymov; Voinot et al. (2024) report -1 ‰ on the same sample. | Uvarova et al. (2014), Variations in the uranium isotopic compositions of uranium ores fr… |
ε205Tl in ε units (parts per 10,000) Values of the same system
Standard : NIST SRM 997
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| −3.4 ± 0.8 ε | 1 | pristine uraninite Single analysis; ± 0.8 (2 SD); sample M19330; IAEA class 2.2 Perigranitic (granite-related); average age used 451 Ma; 64.91 % U, 3.63 µg/g Tl, 35.27 µg/g Mo. | Voinot et al. (2024), Tl, Mo and U isotopes in U-ore deposits record Earth's fundamental … | |
| −4 ± 0.6 ε | 1 | uraninite Single analysis; ± 0.6 (2 SD); full-procedure duplicate at -3.7 ± 0.7; sample M9176A; IAEA class 2.2 Perigranitic (granite-related); average age used 451 Ma; 87.56 % U, 35.32 µg/g Tl, 63.52 µg/g Mo. | Voinot et al. (2024), Tl, Mo and U isotopes in U-ore deposits record Earth's fundamental … |
δ97Mo in ‰ (per mil) Values of the same system
Standard : NIST SRM 3134
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| 0.8 ± 0.09 ‰ | 1 | pristine uraninite Single analysis; ± 0.09 (2 SD); sample M19330; IAEA class 2.2 Perigranitic (granite-related); average age used 451 Ma; 64.91 % U, 3.63 µg/g Tl, 35.27 µg/g Mo. | Voinot et al. (2024), Tl, Mo and U isotopes in U-ore deposits record Earth's fundamental … | |
| 1.3 ± 0.1 ‰ | 1 | uraninite Single analysis; ± 0.1 (2 SD); full-procedure duplicate at +1.3 ± 0.1; sample M9176A; IAEA class 2.2 Perigranitic (granite-related); average age used 451 Ma; 87.56 % U, 35.32 µg/g Tl, 63.52 µg/g Mo. | Voinot et al. (2024), Tl, Mo and U isotopes in U-ore deposits record Earth's fundamental … |
Deposits of the same type
- Schlema-Alberoda Germany
- Příbram (uranium district) Czechia
- Stráž pod Ralskem Czechia
- Zálesí Czechia
- Rophin France
- Littleham Cove (Devon) United Kingdom
- Ty Gallen France
- Guarda uranium province (site 1) Portugal
Cite this page
IsoFind Atlas (2026). Jáchymov, isotope signatures. https://www.isofind.tech/isotopes/en/deposits/jachymov/ (accessed 2026-10-16).
@misc{isofind2026jachymovisotopesignatures,
title = {Jáchymov, isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/deposits/jachymov/},
note = {Accessed 2026-10-16}
}Updated : 2026-10-16