The haüynophyre is a sulfur-rich differentiated lava flow erupted from a parasitic vent of the Vulture volcano (Potenza-Italy). This porphyritic lithotype (43 vol%) is characterised by a very high content (20-30 vol%) of feldspathoids belonging to the sodalite group. Chemical and structural analysis of the sodalite-group minerals has led to the identification of i) a colourless to white nosean, ii) a blue to light-blue haüyne, and iii) a black to grey haüyne. Numerous phenocrysts present a resorbed core and/or a pronounced concentric division into zones with a complex colour sequence. The X-ray diffraction study (XRPD through Gandolfi technique and single crystal structure refinements) has confirmed the occurrence of nosean and has allowed to discard the presence of lazurite. All the analysed crystals, those chromatically homogeneous as well as the zoned ones, have marked core-rim chemical variations. Nosean crystals contain small pyrite inclusions and are characterised by an evolution from a Ca-K poor core to Ca-K rich rim. K_2O content increases towards the rim in blue haüyne, while Na_2O/CaO ratio remains almost constant. Black haüyne has chemical characteristics intermediate between the nosean and the blue haüyne-end members and has the highest S/Cl ratio in the core. Black and blue haüyne have similar patterns of depletion in REE and most other highly lithophile elements relative to the bulk rock. Positive anomaly for the Eu content and spinel composition are indicative of high fO_2 conditions in the magmas in which both haüyne varieties formed. Higher contents of compatible (Sr, Ba) and semicompatible (Ta) elements characterise the black phase. A high Fe content in the black variety could be at least in part responsible for the chromatic difference. Limited contamination by sedimentary evaporites and probably mixing between a sulfur-rich black haüyne-bearing magma and a more cooled magma having stable blue haüyne and nosean is proposed to explain the observed chemical and textural variability. Thin, SO_4-poor and Cl-rich opaque rims having a nosean to sodalite composition and a skeletal texture are found on all the sodalite-group phases. This outer rim is interpreted as due to rapid crystallization driven by exsolution of a sulphur-rich vapour phase.