Nannoniite, Al₂(OH)₅F, is a new mineral species discovered in the Cetine di Cotorniano mine (Tuscany, Italy). Its description was possible through a multi-technique approach, and its crystal structure was solved through three-dimensional electron diffraction, revealing close relations with gibbsite. The partial replacement of (OH) by F induces subtle by detectable structural changes. This study reveals that Al hydroxides could be a source of F in geological environments.

Karlseifertite is a new member of the dussertite group of the alunite supergroup from Tsumeb, Namibia. It is the first member of the dussertite group to be described based upon valency-imposed double site occupancy in the octahedrally coordinated cation site. It is also the first member of the alunite supergroup containing essential Ge. 

A new sulfosalt mineral species, lazerckerite, Ag_3.7Pb_4.6(Sb_7.9Bi_3.8)_Σ11.7S₂₄, has been found, identified, structurally solved, and approved by the IMA. The mineral belongs to the Sb–Bi mixed members of the andorite branch of the lillianite homologous series. The description and characterization of the mineral are presented, and the ways of distinguishing the mineral from other similar members of the group on the basis of chemical results are explained.

Rotherkopfite is the first member of the neptunite group that does not contain lithium in its chemical formula. It was found at Rother Kopf, Eifel volcanic fields, Germany, where in occurs in cavities in a quartz–sanidine fragment embedded in a volcanic rock. Rotherkopfite occurs as dark brownish-red crystals, up to about 0.2 mm across. The intriguing crystal structure is based on two interwoven three-dimensional frameworks.

Zvěstovite-(Fe) is a new, Ag-rich, member of the tetrahedrite group, the most widespread sulfosalts in ore deposits. Its discovery stresses the chemical variability of this mineral group, allowing for a better understanding of the structural plasticity of these compounds, which are able to host a plethora of different elements typical of hydrothermal environments. 

In this paper, the full description of the extremely rare [Ag₆]⁴⁺-cluster-containing new tetrahedrite-group mineral kenoargentotetrahedrite-(Zn) is reported. The structure refinement result confirms the coupling between the site occupancy factor of subvalent hexasilver clusters at the M(2) site and that of the vacancy at the S(2) site. This relationship further substantiates the charge balance substitution mechanism of S-deficiency tetrahedrites: 6^M(2)Ag⁺ + ^S(2)S^2– = ^M(2)[Ag₆]⁴⁺ + ^S(2)□.

The new mineral heimite was originally discovered on the mine dumps of the Grosses Chalttal deposit, Mürtschenalp district, Glarus, Switzerland. Its relatively simple chemistry is formed by water and ions of lead, copper, arsenic, hydrogen and oxygen. The mineral's crystal structure is related to the well-known duftite, which is also observed to grow on crystals of heimite. While heimite has so far only been found in the central Alps, it is expected to occur in other copper deposits worldwide.

The paper proposes an application called OxyEMG (Oxyspinel group End-Member Generator), which is an improved version of EMG. This tool allows for calculating the portions of 31 end-members of the oxyspinel group from data obtained with an electron microprobe. This is fundamental since this group of minerals is considered to be tectonic tracers; their integral composition should be taken into account and not only those end-members that make up the magnetite or ulvöspinel prisms.

We report the description and the characterization of a new mineral species, found in a rock sample from the geological formation called the Pilanesberg Complex, South Africa. This is a silicate mineral that contains a significant amount of sodium, calcium, iron, titanium and fluorine. Its atomic structure shows that it is related to other wöhlerite-group minerals. This work provides new insights into the crystallization conditions that ruled the formation of the Pilanesberg complex.

This article introduces a new nomenclature system for the cerite group minerals. This system was necessary to allow the nomenclature of new species of minerals that are currently being described.

We present the description of new mineral – a Cd-dominant member of the tetrahedrite group, tetrahedrite-(Cd), from the Radětice deposit near Příbram, Czech Republic. All necessary data including crystal structure were successfully determined, and the mineral and its name have been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (number 2022-115).

The paper describes the formal establishment of the paulkerrite group of minerals and its nomenclature. It includes the application of a site-merging procedure, coupled with a site-total-charge analysis, to obtain unambiguous end-member formulae. Application of the procedure has resulted in the revision of the end-member formulae for several of the group members.

Batoniite is a new mineral species belonging to the Al₂O₃–SO₃–H₂O ternary system, first found in the Cetine di Cotorniano Mine (Tuscany, Italy). This hydrated Al sulfate shows a novel crystal structure, characterized by Al octamers, so far reported in only synthetic compounds.

There are unresolved problems related to the nomenclature and identification of mineral species belonging to the triphylite group of minerals. They can be solved by discarding the traditional views on succession of mineral species during oxidation. In other words, it is necessary to separate the concepts of the origin of the mineral and the boundaries of the species.

Dutrowite is the first tourmaline supergroup minerals having Ti as a species-defining chemical constituent. Its finding improves our knowledge on the crystal chemistry of this important mineral group and allows us to achieve a better picture of the mechanisms favouring the incorporation of Ti.