Dayakou
Southeastern Yunnan, Malipo district (Laojunshan metamorphic dome), China
Other hydrothermalémeraude (Be)
- Type
- Emerald in quartz veins and pegmatite dykes hosted by schists
China's only mined emerald deposit, in Neoproterozoic schists and granofels of the Saxi Formation; about thirty pegmatite dykes (80 % of the emeralds, pale) and hydrothermal quartz veins (gem-quality emeralds). Muscovite and biotite dated around 124 Ma (Ar-Ar); the younger Kouha granite cannot be the source, a concealed Cretaceous granite is inferred. Long et al. (2021): dravitic tourmaline from -15.8 to -10.4 ‰, magmatic or metamorphic fluid.
δ11B in ‰ (per mil) Values of the same system
Standard : NIST SRM 951
| Value | Range | n | Mineral or matrix | Source |
|---|---|---|---|---|
| −13 ± 1.6 ‰ | −15.7 / −10.4 ‰ | 23 | tourmaline of emerald-bearing veins in biotite and two-mica schists (type Ia) Mean and standard deviation recalculated from 23 analyses, -15.7 to -10.4 (FZ-2-1-1 c -15.7; FZ-2-3-1 c -12.3; FZ-2-3-3 c -10.6; FZ-2-4-1 c -11.4; FZ-2-4-3 c -12.2; FZ-2-4-5 c -10.7; FZ-2-1-2 b -14.4; FZ-2-3-2 b -12.8; FZ-2-4-2 b -11.3; FZ-2-4-4 b -12.0; FZ-2-4-6 b -10.4; FZ-6-2-1 c -15.0; FZ-6-2-3 c -13.8; FZ-6-2-4 c -12.2; FZ-6-2-2 b -14.2; FZ-6-2-6 b -11.4; FZ-6-2-5 t -12.0; FZ-3b-1-1 c -13.3; FZ-3b-1-3 c -14.8; FZ-3b-1-5 c -14.6; FZ-3b-1-2 b -14.5; FZ-3b-1-4 b -14.8; FZ-3b-1-6 b -14.7). Core (c), rim (b) and transition zone (t). | Long et al. (2021), Ore formation of the Dayakou emerald deposit (Southwest China) constr… |
| −14.4 ± 1.3 ‰ | −15.8 / −12.6 ‰ | 9 | tourmaline of emerald-bearing veins in granofels (type Ib) Mean and standard deviation recalculated from 9 analyses, -15.8 to -12.6 (FZ-4-4-1 c -15.8; FZ-4-4-3 c -14.7; FZ-4-4-5 c -15.7; FZ-4-4-7 c -13.1; FZ-4-4-8 c -12.6; FZ-4-4-2 b -15.7; FZ-4-4-4 b -14.8; FZ-4-4-6 b -14.8; FZ-4-4-9 b -12.7). Core (c), rim (b) and transition zone (t). Type I as a whole (32 analyses, Ia and Ib) has a published mean of -13.4 ± 1.6 ‰. | Long et al. (2021), Ore formation of the Dayakou emerald deposit (Southwest China) constr… |
| −12.9 ± 0.6 ‰ | −13.8 / −11.7 ‰ | 14 | tourmaline of barren quartz veins (type II) Mean and standard deviation recalculated from 14 analyses, -13.8 to -11.7 (SX-EWK-1-1 c -12.5; SX-EWK-3-1 c -12.5; SX-EWK-3-3 c -11.7; SX-EWK-3-5 c -13.4; SX-EWK-3-7 c -13.8; SX-EWK-4-1 c -13.6; SX-EWK-4-3 c -12.7; SX-EWK-4-5 c -13.1; SX-EWK-1-2 b -12.4; SX-EWK-3-2 b -12.8; SX-EWK-3-4 b -12.8; SX-EWK-3-8 b -13.8; SX-EWK-4-2 b -12.4; SX-EWK-4-4 b -12.5). Core (c), rim (b) and transition zone (t). Published mean -12.8 ± 0.6 ‰; the recalculated mean (-12.857) rounds to -12.9. | Long et al. (2021), Ore formation of the Dayakou emerald deposit (Southwest China) constr… |
Deposits of the same type
Cite this page
IsoFind Atlas (2026). Dayakou, isotope signatures. https://www.isofind.tech/isotopes/en/deposits/dayakou/ (accessed 2026-10-20).
@misc{isofind2026dayakouisotopesignatures,
title = {Dayakou, isotope signatures},
author = {{IsoFind Atlas}},
year = {2026},
url = {https://www.isofind.tech/isotopes/en/deposits/dayakou/},
note = {Accessed 2026-10-20}
}Updated : 2026-10-20