Sapphire from Andranondambo, Madagascar

first published in Facette 22 (February 2016)

Figure 1: Sapphire from Andranondambo (Madagascar). Photo: SSEF

In 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 as royal blue and a highly attractive velvety appearance due to submicroscopic dispersed inclusions, in some ways similar to what is also highly appreciated in sapphires from Kashmir.

Figure 2: Dark blue colour zone in a sapphire from Andranondambo (SSEF reference collection), as it is characteristic for this sapphire deposit. Photo: M. S. Krzemnicki, SSEF

But in contrast to sapphires from Kashmir, the investigated sapphire exhibited a dark blue dense colour zone (parallel to the basal pinacoid, Figure 2) located at its girdle, a feature characteristic for ‘Kashmir-like’ sapphires from Andranondambo in Southeast Madagascar (Kiefert et al. 1996, Krzemnicki, SSEF Facette 20, 2013). In combination with further inclusion features and the analysed chemical and spectral properties, the origin of this unheated sapphire was readily concluded.

Sapphire mining in Andranondambo, SE-Madagascar. Photo: Michael Krzemnicki, SSEF