TY - JOUR
T1 - Transmission X-ray diffraction as a new tool for diamond fluid inclusion studies
AU - Smith, E. M.
AU - Kopylova, M. G.
AU - Dubrovinsky, L.
AU - Navon, O.
AU - Ryder, J.
AU - Tomlinson, E. L.
PY - 2011/10
Y1 - 2011/10
N2 - Transmission X-ray diffraction is demonstrated as a new tool for examining daughter minerals within sub-micrometre-size fluid inclusions in fibrous diamond. In transmission geometry, the X-ray beam passes through the sample, interacting with a volume of material. Fibrous diamonds from Mbuji-Mayi, Democratic Republic of Congo; the Wawa area, Ontario, Canada; and the Panda kimberlite, Ekati Mine, Northwest Territories and the Jericho kimberlite, Nunavut, Canada were analysed using X-rays from a high-brilliance lab source and a synchrotron source. Daughter minerals present include the mica-group mineral celadonite, sylvite, halite, dolomite and other carbonates. This represents the first positive identification of halide minerals in fibrous diamond. Mineral inclusions such as forsteritic olivine and pyrope garnet were also found. Unexpectedly, daughter minerals were identified in only ten of the 38 diamonds analysed, despite their concentrations being greater than experimentally proven detection limits. The presence of significant amounts of amorphous or dissolved material appears unlikely, but cannot be ruled out. Alternatively, the results may indicate a wide variety of related daughter minerals, such that most phases fall below the detection limits. Transmission X-ray diffraction should be applied cautiously to the study of fibrous diamond, as it provides an incomplete account of the fluid-inclusion mineralogy.
AB - Transmission X-ray diffraction is demonstrated as a new tool for examining daughter minerals within sub-micrometre-size fluid inclusions in fibrous diamond. In transmission geometry, the X-ray beam passes through the sample, interacting with a volume of material. Fibrous diamonds from Mbuji-Mayi, Democratic Republic of Congo; the Wawa area, Ontario, Canada; and the Panda kimberlite, Ekati Mine, Northwest Territories and the Jericho kimberlite, Nunavut, Canada were analysed using X-rays from a high-brilliance lab source and a synchrotron source. Daughter minerals present include the mica-group mineral celadonite, sylvite, halite, dolomite and other carbonates. This represents the first positive identification of halide minerals in fibrous diamond. Mineral inclusions such as forsteritic olivine and pyrope garnet were also found. Unexpectedly, daughter minerals were identified in only ten of the 38 diamonds analysed, despite their concentrations being greater than experimentally proven detection limits. The presence of significant amounts of amorphous or dissolved material appears unlikely, but cannot be ruled out. Alternatively, the results may indicate a wide variety of related daughter minerals, such that most phases fall below the detection limits. Transmission X-ray diffraction should be applied cautiously to the study of fibrous diamond, as it provides an incomplete account of the fluid-inclusion mineralogy.
KW - Daughter mineral
KW - Fibrous diamond
KW - Fluid inclusion
KW - Synchrotron
KW - X-ray diffraction
UR - http://www.scopus.com/inward/record.url?scp=84858802436&partnerID=8YFLogxK
U2 - 10.1180/minmag.2011.075.5.2657
DO - 10.1180/minmag.2011.075.5.2657
M3 - Article
AN - SCOPUS:84858802436
SN - 0026-461X
VL - 75
SP - 2657
EP - 2675
JO - Mineralogical Magazine
JF - Mineralogical Magazine
IS - 5
ER -