Epsilon-Nd (εNd)
Definition
The 143Nd/144Nd ratio of a sample expressed as a deviation in parts per ten thousand from the chondritic uniform reservoir (CHUR). Positive values indicate juvenile crustal or mantle derivation; negative values indicate ancient, Nd-depleted crust. The parameter tracks crustal age and magmatic history independently of Rb-Sr.
Related terms
- Conflict mineral
- A mineral whose extraction or trade finances armed conflict. The OECD defines 3TG (tin, tantalum, tungsten, gold) from conflict-affected and high-risk areas...
- Inclusion fingerprinting
- Identification of mineral inclusions trapped inside a gemstone during growth as indicators of the geological environment. Marble-hosted rubies typically contain calcite and...
- Kimberley Process (KPCS)
- An international certification scheme launched in 2003 that requires participant countries to certify that rough diamonds are conflict-free before export. Isotope and...
- LA-ICP-MS trace-element profiling
- Laser ablation inductively coupled plasma mass spectrometry applied directly to a polished gemstone surface. It measures dozens of trace elements simultaneously in...
- REE pattern (rare earth element pattern)
- A plot of rare earth element concentrations normalised to chondrite or primitive mantle, showing the relative enrichment or depletion of each REE...
Explained in
- Isotope Systems for Gem and Mineral ProvenanceThe 143Nd/144Nd ratio of a sample expressed as a deviation in parts per ten thousand from the chondritic uniform reservoir (CHUR). Positive values indicate juv...