Specimen data for Montebrasite

Tom Mortimer catalog number: 1659

Identification method: Tests for Montebrasite/Ambligonite: Fuses easily to white blob that is fluorescent. This material responds correctly to this test.

Notes: Montebrasite and Ambligonite are visually indistinguishable. To author's knowledge, all previously identified New Hampshire Ambligonite is Montebrasite. In a mine dump situation, Montebrasite can be difficult to distinguish from feldspar. Montebrasite lacks feldspar's pearly cleavage.
EDS plot by Excalibur Mineral Corp below is for the Chickering Mine specimen. Analysis report stated: "isolation of phosphate mineral suggests montebrasite rather than ambligonite due to the low fluorine content found in the samples analyzed."