Journal
GEMS & GEMOLOGY
Volume 55, Issue 4, Pages 648-659Publisher
GEMOLOGICAL INST AMER
DOI: 10.5741/GEMS.55.4.648
Keywords
-
Categories
Funding
- National Science Foundation [EAR-1551434]
Ask authors/readers for more resources
Vivid blue to green copper-bearing tourmalines, known as Paraiba tourmalines, are recovered from deposits in Brazil, Nigeria, and Mozambique. These tourmalines are sought after for their intense colors. Prices are based, in part, on the geographic origin of a stone, and determining provenance is thus an important aspect for Paraiba tourmaline. However, their geographic origin cannot be established by standard gemological testing and/or qualitative chemical analyses. GIA has established sophisticated criteria requiring quantitative chemical analyses to determine geographic origin for these tourmalines. These criteria were based on several hundred samples from known sources spanning the three countries. Highly accurate and precise quantitative elemental concentrations for Cu, Zn, Ga, Sr, Sn, and Pb are acquired with laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). These data can then be plotted as a function of elemental concentration for accurate geographic origin determination.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available