A both wild and farmed mussels in natural conditions, anthropogenic inputs are usually reflected in the increase of the content of specific elements. To determine the possible effect of the elemental patterns of farmed and wild mussels (Mytilus galloprovincialis) collected in the Saldanha Bay area (South Africa) on the crystallographic texture of the shells, the content of 20 elements in shells and 24 in the soft tissue of mussels was determined by neutron activation analysis. The crystallographic texture of mussel shells was analyzed using time-of-flight neutron diffraction. The wild mussels from open ocean site live in stressful natural conditions and contain higher amounts of the majority of determined elements in comparison with mussels farmed in closed water areas with anthropogenic loadings. The changes between the maximums of the same pole figures of the three samples are in the range of variability identified for the genus Mytilus. The content of Cl, Sr, and I was the highest in mussels from the open ocean site, which is reflected by the lowest mass/length ratio. The determined crystallographic textures of mussels are relatively stable as shown in the analyzed pole figures despite the concentrations of Na, Mg, Cl, Br, Sr, and I in shells, which significantly differ for wild and farmed mussels. The stability of the crystallographic texture that we observed suggests that it can be used as a reference model, where if a very different texture is determined, increased attention to the ecological situation should be paid.

Bivalve shells exhibit extreme mechanical resistance despite using a minimal amount of material. The shells thus represent an inspiration and a source of information for environmental, geological, and engineering sciences. In this study, two species of freshwater shells from the Unionidae family, collected in the Czech Luznice River, were investigated with respect to their crystallographic preferred orientation by means of X-ray and neutron diffraction. The observed texture was found to be of a strongly uniaxial type, with the strength increasing along the shell growth direction. The c-axis of aragonite does not change during growth and its alignment remains perpendicular to the outer surface of the shell

It is assumed that the crystallographic texture of minerals in the shells of recent and fossil mollusks is very stable. To check this, it is necessary to examine the shells of animals that had lain in sediments for millions of years and lived in different conditions. It is revealed that the crystallographic texture of calcite in the shells of Gryphaea dilatata from deposits from the Middle Callovian–Lower Oxfordian (Jurassic), which lived in different water areas, is not affected by habitat conditions and the fossilization process. The crystallographic texture was studied using pole figures measured by neutron diffraction. The neutron diffraction method makes it possible to study the crystallographic texture in large samples—up to 100 cm³ in volume without destroying them. The recrystallization features of the G. dilatata valve, which affect the crystallographic texture, were discovered for the first time. This is determined from the isolines appearance of pole figures. The crystallographic texture of the G. dilatata mollusks’ different valves vary depending on their shape. The pole figures of calcite in the thick-walled valves of G. dilatata, Pycnodonte mirabilis, and Ostrea edulis are close to axial and display weak crystallographic texture.

The crystallographic texture of the whole valves of bivalve mollusks from the family Unionidae Unio pictorum Linnaeus, 1758 and Anodonta cygnea Linnaeus, 1758 is studied using pole figures measured using neutron diffraction. The use of neutron diffraction, in contrast to X-rays, makes it possible to study the valves without destroying them. Thus, we can discuss the study of the global texture of the entire valve. It was revealed that the pole figures of aragonite in the valves repeat their shape. The pole density maxima for U. pictorum from the Danube Delta and the Gulf of Finland in the Baltic Sea, living at different salinities and temperatures, differs by 0.41 mrd. The maximum value of the crystallographic texture for A. cygnea from the Danube Delta was also measured (5.07 mrd). In terms of texture sharpness, it surpasses the shell of marine bivalve mollusks, which are partially or completely composed of aragonite. Although U. pictorum and Mya arenaria Linnaeus, 1758 have different microstructures, their pole figures are very similar in isolines pattern, but differ in pole density maxima. No relationship was found between the crystallographic texture and the microstructure in U. pictorum. In addition, we report good qualitative agreement between aragonite X-ray pole figures of Sinanodonta woodiana Lea, 1834 from the Czech river Luznice, and neutron pole figures of U. pictorum from the Danube Delta.