Figure 1: Cultured pearl necklace containing one natural pearl. Photo: V. Lanzafame, SSEF.Testing pearl necklaces can be rather painstaking work, as at least two gemmologists at SSEF meticulously and individually check a necklace pearl by pearl, with the aim of finding one (or...
by Dr. M.S. Krzemnicki, first published in Facette 26 (May 2020)Figure 1: Sciacca coral item from which beads were selected for age dating. Also in this picture are two pieces of raw corallium rubrum. Photo: M. Bichsel, SSEF.Since 2017, the Swiss Gemmological...
by Dr. L. Speich, first published in Facette 26 (May 2020)Figure 1: Distribution of nitrogen in an elongated diamond from the Mir mine (Siberia) resembling growth rings in a tree. Analysis shows that this diamond has experienced temperatures between 1175 and 1125˚C. Length...
Based on real case studies on sapphire and emerald specimens, we here present how a simultaneous multi-element approach assists origin determination. Instead of pre-defining a list of isotopes in advance, routine analysis of blue sapphires using LA-ICP-TOF-MS detects rarely occurring trace elements such as beryllium...
Figure 1: A sample of rough deep purple Vesuvianite (4 cm) from northern Pakistan and cabochon of 10.73 ct. Photo: H.A. Hänniby Prof. H.A. Hänni, first published in Facette 26 (May 2020)stan has a number of gemstone deposits that are related to the collision of the Indian continent...
In early 2019, an Australian client submitted a small series of gem- quality light green emeralds ranging from 2.01 – 5.80 ct in weight, which reportedly originated from the same rough crystal from the Riverina deposit in Western Australia (Figure 1). Known since the late...
Spodumene crystals (longest item about 50 cm long and 5.9 kg heavy) submitted to SSEF as new 'emeralds' from Pakistan shown here together with a...
DNA fingerprinting of ivory involves a scientific method that can provide valuable information about the species of ivory being used in jewellery and ornamental objects, in order to determine whether it is CITES- listed elephant ivory or non-listed mammoth ivory. DNA fingerprinting, together with a...
by Dr. M.S. Krzemnicki, first published in Facette 26 (May 2020)Radiometric age dating is a well-established method in geochronology (Earth sciences) and archaeology. There are numerous studies highlighting the use of radioactive decay of U-Pb, K-Ar (amongst many others) for geological age dating...
first published in Facette 22 (February 2016)Figure 1: Sapphire from Andranondambo (Madagascar). Photo: SSEFIn 2016, the SSEF received a sapphire of exceptional quality and size for testing (Figure 1). The sapphire of 33 ct was characterised by a saturated blue colour, - poetically also known...