This is the raw greenish-yellow francolite specimen. Dimensions: 1.3 x 1.1 x 0.8″ (3.2 x 2.8 x 2cm). Weight – 0.7oz (21 grams). Origin: Russia, Yakutia.
Some information about francolite:
Francolite is a carbonate rich variety of the mineral fluorapatite and is present in most sedimentary phosphorites. It has a variable chemical composition which represented by (Ca,Mg,Sr,Na)10(PO4,SO4,CO3)6F2-3. The mineral named after its occurrence at Wheal Franco, Whitchurch, Tavistock District, Devon, England.