Gem News International Gems & Gemology, Fall 2008, Vol. 44, No. 3

An Interesting Rose Quartz from Madagascar

IMG-FA08-GNI 76771 636x358
Figure 36. This 3.83 ct rose quartz from southern Madagascar contains an inclusion suite that has not previously been documented in such material from any locality. GIA Collection no. 37702; photo by Robert Weldon.
In October 2007, Fabrice Danet (Style Gems, Antsirabe, Madagascar) informed us about a new find of rose quartz from Madagascar that contained some unusual inclusions. He first saw the material in April 2007, when a local dealer offered him a few kilograms of rather small pieces said to be morganite. About half the rough contained noticeable green inclusions, and Mr. Danet subsequently purchased 2 kg. In June 2008, he obtained 10 kg from a 100 kg parcel consisting mostly of small pieces. This time it was offered as rose quartz by a man who actually mined the material. He reported that it came from several small pits in a weathered pegmatite that contained beryl, black tourmaline, mica, clay, and areas of rose quartz. According to the miner and several local dealers, the deposit is located in the Ihosy area of southern Madagascar.

So far, Mr. Danet has cut about 200 stones, the largest of which weighs 27 ct. On examining the material with a loupe, he noticed that the green inclusions had a shape and color that were typical of diopside. Also present were orange hessonite-like inclusions and some very thin needles.

Mr. Danet donated to GIA a light pink 3.83 ct oval brilliant cut (figure 36) and three pieces of rough that contained obvious dark green and bright orange transparent-to-translucent inclusions. The faceted gem was confirmed as rose quartz by standard gemological testing. It contained a relatively large green inclusion adjacent to an orange inclusion (figure 37) that were both visible through the table facet and made excellent targets for Raman microanalysis. As suggested by Mr. Danet, the green inclusions were indeed diopside and the orange crystals were grossular. While we have encountered garnets before as inclusions in rose quartz (from Sri Lanka), this is the first time this combination of inclusions has been observed in rose quartz from any locality. As an added bonus, the very small blade-like to acicular inclusions in the stone were identified as epidote.

IMG-FA08-GNI 76770 636x358
Figure 37. The green inclusions in this rose quartz from Madagascar proved to be diopside, and the orange crystalline masses were identified as grossular. Also present are some needles of epidote. Photomicrograph by J. I. Koivula; field of view 2.7 mm.