The aim of this review article on recent developments of mechanochemistry (nowadays established as a part of chemistry) is to provide a comprehensive overview of advances achieved in the field of atomistic processes, phase transformations, simple and multicomponent nanosystems and peculiarities of mechanochemical reactions. Industrial aspects with successful penetration into fields like materials engineering, heterogeneous catalysis and extractive metallurgy are also reviewed. The hallmarks of mechanochemistry include influencing reactivity of solids by the presence of solid-state defects, interphases and relaxation phenomena, enabling processes to take place under non-equilibrium conditions, creating a well-crystallized core of nanoparticles with disordered near-surface shell regions and performing simple dry time-convenient one-step syntheses. Underlying these hallmarks are technological consequences like preparing new nanomaterials with the desired properties or producing these materials in a reproducible way with high yield and under simple and easy operating conditions. The last but not least hallmark is enabling work under environmentally friendly and essentially waste-free conditions (822 references).

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Hallmarks of mechanochemistry: From nanoparticles to technology

Plastic deformation behavior of Mg12YZn with 18R long-period stacking ordered structure

“It is plain that almost all kinds of atramentum are made of Earth and Water At first they were liquid and afterwards solid, and still they can be redissolved, by heat and moisture” Albertus Magnus (1205–1280) Book of Minerals (transl D Wyckoff, 1967) 

The observation of “efflorescences,” or the flowering of salts, associated with periods of dryness in soils, in closed-basin lakes, in rock outcrops, and in mines and mine wastes has been noted since early antiquity The formation of metal-sulfate salts, in connection with the mining of metals, was a phenomenon well known to the early Greek and Roman civilizations Alum, most commonly potash alum KAl(SO4)2 · 12H2O, which is from the Latin alumen , was extensively mined and used by goldsmiths, dyers, paper manufacturers, and physicians in ancient civilizations It forms from the oxidation of pyrite in shales and slates and from oxidation of sulfurous gases in geothermal areas The Greeks and the Romans described stalactites of atramentum (soluble metal-sulfate salts) that formed within mines and along rock faces (Agricola 1546, 1556) Furthermore, the toxic effects of these salts on animals were also noted For example, in De Natura Fossilium , Agricola (1546) stated “…I mention the congealed acid juice which usually produces cadmia  It is white, hard, and so acrid that it can eat away walls, grills and even destroy all living matter” Cadmia is thought to be derived from the oxidation of zinc, cobalt, and arsenic sulfides, such as cobaltite He goes on to say that “Pyrite, unless it contains sulphates, is either a golden or silver color, rarely any other, while cadmia is black, yellow brown, or gray The former will cure gatherings while the latter is a deadly poison and will destroy any living substance It is used …

Metal-sulfate Salts from Sulfide Mineral Oxidation

We studied intracellular magnetite particles produced by several morphological types of magnetotactic bacteria including the spirillar (helical) freshwater species, Magnetospirillum magnetotacticum, and four incompletely characterized marine strains: MV-1, a curved rod-shaped bacterium; MC-1 and MC-2, two coccoid (spherical) microorganisms; and MV-4, a spirillum. Particle morphologies, size distributions, and structural features were examined using conventional and high-resolution transmission electron microscopy. The various strains produce crystals with characteristic shapes. All habits can be derived from various combinations of the isometric {111}, {110}, and {100} forms. We compared the size and shape distributions of crystals from magnetotactic bacteria with those of synthetic magnetite grains of similar size and found the biogenic and synthetic distributions to be statistically distinguishable. In particular, the size distributions of the bacterial magnetite crystals are narrower and have a distribution asymmetry that is the opposite of the nonbiogenic sample. The only deviation from ideal structure in the bacterial magnetite seems to be the occurrence of spinel-law twins. Sparse multiple twins were also observed. Because the synthetic magnetite crystals contain twins similar to those in bacteria, in the absence of characteristic chains of crystals, only the size and shape distributions seem to be useful for distinguishing bacterial from nonbiogenic magnetite.

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Magnetite from magnetotactic bacteria; size distributions and twinning

Biological mineralization processes are extremely diverse and, to date, it is an act of faith rather than an established principle that organisms utilize common mechanisms for forming crystals. A systematic analysis of the structural organization, as far as possible at the molecular level, of five different extracellularly mineralized tissues is presented to demonstrate that at least these mineralization processes are all part of the same continuum. The degrees of control exercised over crystal nucleation and crystal growth modulation are the basic variables. The five tissues, extracellularly mineralizing algae, radial and granular foraminifera, mammalian bone, mammalian enamel, and mollusk shell nacre, probably span the entire spectrum. Their crystal shapes, sizes, and the relations between the mineral phase and the organic phase, are primarily used to assess probable degrees of control exercised over crystal nucleation and modulation. Three different types of nucleation processes can be recognized: nonspecific, stereochemical, and epitaxial. Modulation of crystal growth after nucleation is either absent, achieved by adsorption of macromolecules onto specific crystal faces, or occurs by the prepositioning of matrix surfaces which interrupt crystal growth. The tissues in which active control is exercised over crystal growth all contain similar types of acidic matrix macromolecules. Significantly, the framework matrix macromolecules are all quite different and hence probably perform some tissue-specific functions. The study shows that there is a common basis for understanding these mineralization processes which is reflected in the nature of the protein-crystal interactions which occur in each tissue.

Organization of extracellularly mineralized tissues: a comparative study of biological crystal growth

The system of mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University, 1837-1892

Three new polymorphs of zinc sulfide are described All are related structurally to wurtzite but difier in that they represent stacking sequences of hexagonal closest-packing of higher periodicity than that of the basic wurtzite structure The latter structure may be designated 2H in the nomenclature of Ramsdell (1947) The new polymorphs correspond to 4H, 6H and 15R, and are isotypic with the corresponding polymorphs of silicon carbide A tabulation of the crystallographic properties follows

http://www.minsocam.org/ammin/AM35/AM35_29.pdf

Three New Polymorphs of Zinc Sulfide

Three new polymorphs of zinc sulfide are described. All are related structurally to wurtzite but difier in that they represent stacking sequences of hexagonal closest-packing of higher periodicity than that of the basic wurtzite structure. The latter structure may be designated 2H in the nomenclature of Ramsdell (1947). The new polymorphs correspond to 4H, 6H and 15R, and are isotypic with the corresponding polymorphs of silicon carbide. A tabulation of the crystallographic properties follows.

Three new polymorphs of zinc sulfide

No satisfactory data for the morphological determination of the symmetry and elements of graphite have hitherto been published. Goldschmidt (1913), unable to decide between Kenngott's hexagonal interpretation of his meager data and the monoclinic interpretation of Nordenskjtild, gives both in the Atlas.The former has, however, been accepted by most authors and the mineral has been described as hexagonal-rhombohedral, the triangular striations commonly to be seen on the base determining its rhombohedrai classification. Recent studies of the structure cell by tc-ray methods lead to the conclusion that graphite is hexagonal (Bragg, 1937) and not rhombohedral, although a trigonal symmetry class is not excluded. The measurements presented in the following pages' made on graphite crystals from Sterling Hill, New Jersey, seem to the writer to yield a definite and unambiguous solution of this problem. Graphite is hexagonal with full symmetry. The graphite crystals from Sterling Hill occur in crystalline limestone in an association to be described on a Iater page. I am indebted for them to Mr. L. H. Bauer of Franklin, New Jersey, who found the material and isolated the best crystals. They are scales up to 1 or 2 rrrm' in diameter, the best ones, however, not exceeding 0.5 mm. The base is extremely brilliant, hexagonal in outline, with edges showing many facets, often very plane and bright, although striated edges are the rule. Of the hundreds of crystals studied, ten were completely measured and yielded the forms and angles shown in Table 1. Four of these crystals were very simple in form and gave closely agreeing measurements for three forms only besides the basal pinacoid, which are regarded as definitely proving the hexagonal symmetry of graphite. They are summarized in Table 2. But one of these crystals showed measurable faces at the lower end, and it was unfortunately lost in attempting to reverse it on the goniometer. Figures 1,2 and.3 represent respectively crystals 1, 3 and 4 of Table 2 in approximately their actual development.

Charles Palache

Papers

The system of mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University, 1837-1892

Three New Polymorphs of Zinc Sulfide

Three new polymorphs of zinc sulfide

Contributions to the mineralogy of sterling hill, new jersey: morphology of graphite, arsenopyrite, pyrite, and arsenic

Halides, nitrates, borates, carbonates, sulfates, phosphates, arsenates, tungstates, molybdates, etc