|Minerals of the Chickering Mine Walpole, NH MONTEBRASITE (Li,Na)AlPO4(OH,F) Back to Chickering front page.|
Specimen owner ID's (capitals): TM = Tom Mortimer, BW = Bob Wilken, BJ = Bob Janules, PC = Peter Cristofono, AW = Anna Wilken
Photographer ID's (lower case).
Identification: MON_1, MON_2 => fusability and fusion after heating (see discussion). EDS analysis was performed by Excalibur Mineral Corp. for a Chickering Mine specimen. Analysis report stated: "isolation of phosphate mineral suggests montebrasite rather than amblygonite due to the low fluorine content found in the samples analyzed." MON_3 => K Day EDS analysis BJ14 (0.04 mm clear xl)
MON_4 => K Day EDS analysis BJ15 (0.04 mm clear xl)
Discussion: Montebrasite is another common phosphate at the Chickering Mine. On the mine dump, it may easily be mistaken for feldspar, but lacks feldspar's cleavage. A grain of montebrasite easily fuses in a tourch flame, while feldspar does not. After heating, the fused areas are fluorescent bright-white in both long and short wave UV. EDS analysis required to distinguish montebrasite from amblygonite.