Epitaxial growths of rutile on a tabular ilmenite crystal pseudomorphized by rutile and hematite. The bright red epitaxial rutile crystals form elbow twins. The pseudomorphized ilmenite crystal has very marked geometric growth forms. Good sized and fine specimen.
Aleksander Rečnik et al. (2015) indicates that this complete transformation involves three successive exsolutions processes: (1) exsolution of ilmenite lamellae from the primary ferrian-ilmenite, (2) exsolution of rutile lamellae from ilmenite triggered by oxidation of ferrous iron and remobilization of cations within the common oxygen sublattice and (3) exsolution of hematite precipitates from Fe-rich rutile lamellae. Remnants of all three processes can still be observed in the samples (Rečnik et al., 2015, Contributions to Mineralogy and Petrology).

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