Inclusions in topaz from miarolitic pegmatites of the Volodarsk-Volynski Massif (Ukraine) – A Raman spectroscopic study

The differently coloured (colourless, brown–pinkish and blue–pinkish) crystals of topaz from granitic pegmatites of Volodarsk-Volynsky Massif (VVM) have been investigated by scanning electron microscopy (SEM) and Raman microspectroscopy (RS) methods. Topaz (287, 522, 855, 929 cm−1), goethite (390 cm−1), pyrite (377–379 cm−1), marcasite (397 and 331 cm−1) and monazite (460 and 970–1070 cm−1) were identified as mineral inclusions in analysed crystals. On the basis of RS spectra some of this inclusions contain also organic matter, represented by carbonaceous matter (D-band at ca. 1320–1340 cm−1 and G-band at ca. 1590–1600 cm−1) and liquid simple hydrocarbons consisting of aliphatic and aromatic groups (1240, 1325 and 1420 cm−1). Other solid phases found the host topaz, i.e. quartz, orthoclase, very rare minerals (micas) as lepidolite, zinnwaldite and also beryl and rutile, were identified with SEM–EDS analyses. All these mineral inclusions have been formed by post-magmatic, fluid-induced processes, extended from pegmatite to hydrothermal stages of magma crystallization.

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► Topaz crystals from granitic pegmatites of Volodarsk-Volynsky (Ukraine) have been examined with SEM–EDS and RS method.
► They contain a wealth of both fluid and solid inclusions.
► The main mineral inclusions are represented by topaz, quartz, feldspar, beryl, Li-bearing micas, goethite, pyrite, rutile.
► In the vicinity of many solid inclusions organic components (liquid hydrocarbons or carbonaceous matter) frequently occur.