Despite the recent advances in minimally invasive surgery, kidney stones still pose a significant clinical challenge due to their high recurrence rate of 50% in 5-10 years after the first stone episode. Using the methods of geosciences and biology, the GeoBioMed approach treats kidney stones as biogenic minerals, offering a novel perspective on their formation and dissolution processes. In this review, we discuss kidney stones' structural and mechanical properties as emerging biomarkers of urolithiasis, emphasizing the importance of a comprehensive stone analysis in developing personalized treatment strategies. By focusing on unexplored properties like crystalline architecture, porosity, permeability, cleavage, and fracture, alongside the conventionally used composition and morphology, we show how these stone characteristics influence the treatment efficacy and the disease recurrence. This review also highlights the potential of advanced imaging techniques to uncover novel biomarkers, contributing to a deeper understanding of stone pathogenesis. We discuss how the interdisciplinary collaboration within the GeoBioMed approach aims to enhance the diagnostic accuracy, improve the treatment outcomes, and reduce the recurrence of urolithiasis.

crystalline structure causes planes of weakness, and the breakage of a mineral along such planes is termed cleavage. The quality of cleavage can be described based In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form. The geological definition of mineral normally excludes compounds that occur only in living organisms. However, some minerals are often biogenic (such as calcite) or chemically organic com Twinni… By definition, minerals have a characteristic atomic arrangement. Weakness in this crystalline structure causes planes of weakness, and the breakage of a mineral along such planes is termed cleavage. The quality of cleavage can be described based on how cleanly and easily the mineral breaks; common descriptors, in order of decreasing quality, are "perfect", "good", "distinct", and "poor". In particularly transparent minerals, or in thin-section, cleavage can be seen as a series of parallel lines marking the planar surfaces when viewed from the side. Cleavage is not a universal property among minerals; for example, quartz, consisting of extensively interconnected silica tetrahedra, does not have a crystallographic weakness which would allow it to cleave. In contrast, micas, which have perfect basal cleavage, consist of sheets of silica tetrahedra which are very weakly held together. As cleavage is a function of crystallography, there are a variety of cleavage types. Cleavage occurs typically in either one, two, three, four, or six directions. Basal cleavage in one direction is a distinctive property of the micas. Two-directional cleavage is described as prismatic, and occurs in minerals such as the amphiboles and pyroxenes. Minerals such as galena or halite have cubic (or isometric) cleavage in three directions, at 90°; when three directions of cleavage are present, but not at 90°, such as in calcite or rhodochrosite, it is termed rhombohedral cleavage. Octahedral cleavage (four directions) is present in fluorite and diamond, and sphalerite has six-directional dodecahedral cleavage. Minerals with many cleavages might not break equally well in all of the directions; for example, calcite has good cleavage in three directions, but gypsum has perfect cleavage in one direction, and poor cleavage in two other directions. Angles between cleavage planes vary between minerals. For example, as the amphiboles are double-chain silicates and the pyroxenes are single-chain silicates, the angle between their cleavage planes is different. The pyroxenes cleave in two directions at approximately 90°, whereas the amphiboles distinctively cleave in two directions separated by…

Colour, lustre and fracture are of especial value in hand-picking, to aid the eye in selecting the mineral sought. Instances are, of colours, the white of quartz, the pale straw colour of felspar, the dull yellow of limonite, the brass yellow of chalcopyrite, the pale metallic yellow of pyrite; of lustres, the vitreous of quartz, the adamantine of diamond and cerussite, the resinous of blende, the earthy of limonite, and the metallic of pyrite; and of fractures, the cleavage planes of felspar and galena, the conchoidal fracture of quartz and pyrite, the granular of some forms of magnetite and blende. Magnetism is a most direct and simple method of separating minerals where it is available. The discovery that by the use of electro-magnets of great power minerals formerly regarded as non-magnetic are attracted, has made it possible to separate several classes of minerals present in an ore; for example, the strongly magnetic mineral may first be taken out, then the mildly magnetic, and last the weakly magnetic, the non-magnetic being left behind.

c. Characters depending on Cohesion.—Some minerals (e.g. a sheet of mica) are highly elastic, springing back to their original shape after being bent. Others (e.g. talc) may be readily bent, but do not return to their original form when released; these are said to be pliable or flexible. Sectile minerals (e.g. chlorargyrite) may be cut with a knife without being fractured: related characters are malleability (e.g. argentite) and ductility (e.g. silver). The tenacity, or degree of frangibility of different minerals varies widely: they may be brittle, tough, soft or friable. The fractured surface produced when a mineral is broken is called the “fracture,” and the kind of fracture is often of determinative value; descriptive terms are: conchoidal (e.g. quartz, which may often be recognized by its glassy conchoidal fracture), sub-conchoidal, uneven, even, splintery (e.g. jade), hackly or with short sharp points (e.g. copper), &c. In many cases when a crystallized mineral is broken it separates in certain definite directions along plane surfaces.

Probably Neolithic flint pick. Dimensions 416 x 66 x 49mm.Brown staining over dark grey / black flint. Rhombic section with sharp ridge on one face, largely formed by a natural cleavage plane. Other face flaked over all and with a more rounded ridge. Colour suggests a probable peaty origin, and there is a trace of concretion on one face.At one end an impact has removed a longitudinal flake which has exposed the underlying flint, but this break does not appear to be recent. Otherwise the artefact is undamaged, but is not sharp.The flint is grainy, giving a dull fracture, but homogenous, with on