Mazzi F, Galli E (1978) Is each analcime different? ANA 2 American Mineralogist 63 448-460 Mazzi F, Galli E (1978) Is each analcime different? ANA 1 American Mineralogist 63 448-460 The Canadian Mineralogist (2019) The Canadian Mineralogist list of symbols for rock- and ore-forming minerals (December 30, 2019). (2010) Abbreviations for names of rock-forming minerals.

IUGS Commission on the Systematics in Petrology. (2007) Recommendations by the IUGS Subcommission on the Systematics of Metamorphic Rocks: List of mineral abbreviations. Older variants are listed for historical use only. Please only use the official IMA–CNMNC symbol. (Andy Christy, 2010)Īs of 2021 there are now IMA–CNMNC approved mineral symbols (abbreviations) for each mineral species, useful for tables and diagrams. There is a slight analogy with hand specimen colour versus streak: a hand specimen can show a range of colours due to trace impurities, but these are diluted out in the small particles of the streak powder, so that only the true inherent colour of the material, much more constant, remains. The crystal structure topology and maximum possible symmetry of the idealised structure are what really matters. Hence, the differences are far too slight to merit multiple species names, and analcime is a common example of a number of minerals which occur in multiple crystal system/space group varieties.

Macroscopically, the crystals always look pseudocubic, apart from the very slight nonzero birefringence and fine lamellar twinning visible in the polarising microscope, because the ordering and crumpling happens in different directions in different lamellae, and over the whole crystal it averages out. The reduction to various lower symmetries occurs because of slight changes in the ordering of Si and Al atoms and slight crumpling of the framework. The mineral occurs in multiple crystal systems but the aluminosilicate framework of the crystal structure does not change in topology at all. Possible unnamed K analogue is known ( 'UM1967-09-SiO:AlHKNa').

Analcime-Pollucite Series and the Analcime-Wairakite Series.

Westland survival basalt rock