This is the raw green-yellow francolite specimen with small staffelite crystals. Dimensions: 2.8 x 1.7 x 1.5″ (7 x 4.2 x 3.7cm). Weight – 3.1oz (88 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.