Strüverite is a variety of rutile rich in tantalum and iron, with the formula (Ti,Ta,Fe)O₂, with variable proportions of niobium (Nb). When the proportion of Ta>Nb is called strüverite, but if Nb≥Ta the variety has been named ilmenorutile. The specimens from this locality in Madagascar have been mainly determined to be of the Ta-rich variety: strüverite. An interesting specimen with a very special chemistry.

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