Growth behaviour of silica/carbonate nanocrystalline composites of calcite and aragonite

Growth behaviour of silica/carbonate nanocrystalline composites of calcite and aragonite

Gan Zhang, Juan Morales and Juan Manuel García-Ruiz, J. Mater. Chem. B, 2017, 5, 1658. Download paper. The precipitation of barium and strontium carbonate in alkaline silica gels or silica solutions produces nanocrystalline self-assembled composite materials displaying biomimetic shapes and textures. We have crystallized concomitantly in time and space two anhydrous polymorphs of calcium carbonate, under similar conditions at different temperatures. The orthorhombic phase aragonite produces nanocrystalline aggregates exhibiting non-crystallographic morphologies and complex textures characteristic…

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Simultaneous growth of biomorphic aragonite and elongated calcite

Simultaneous growth of biomorphic aragonite and elongated calcite

The micrographs are extracted from images sequence of a time-lapse video of the simultaneous growth of biomorphic aragonite in elongated calcite in alkaline silica gel. The video was recorded by an optical microscope (Nikon AZ100) with Nikon AZ-Plan Apo 4x objective lens and Nikon digital sight DS-Fi1 camera. The images were captured at constant time intervals (30 minutes) by using NIS-Elements BR, and acquired images sequences were converted to video by ImageJ. The crystallization of…

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Three study cases of growth morphology in minerals: Halite, calcite and gypsum

Three study cases of growth morphology in minerals: Halite, calcite and gypsum

Aquilano, D.; Otálora, F.; Pastero, L.; García-Ruiz, J. M., Progress in Crystal Growth and Characterization of Materials 2016, 62 (2), 227-251. Download paper. Beyond fundamental aspects of crystal growth and morphology, the growth of minerals is a challenging subject because in most cases we face a problem with unknown growth conditions. Actually, in the field of geological studies, we have to decipher the growth conditions of a crystal using the information contained in the very…

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FELLOWSHIP OPPORTUNITY on MINERAL ORGANIC INTERACTIONS AND SELF-ASSEMBLY IN EXTREME CHEMICAL ENVIRONMENTS A Ph.D. position is offered at the Laboratorio de Estudios Cristalográficos (LEC) in Granada (Spain). We are looking for exceptionally motivated Ph.D. candidates with a keen interest in mineral genesis, mineral growth pattern, early Earth, life detection and origin of life. The thesis will be supervised by Prof.  Juan Manuel Garcia-Ruiz The selected candidate will work for 3 years in an international and…

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The role of CaCO3o neutral pair in calcium carbonate crystallization

The role of CaCO3o neutral pair in calcium carbonate crystallization

Genovese, D.; Montalti, M.; Otálora, F.; Gómez-Morales, J.; Sancho-Tomás, M.; Falini, G.; García-Ruiz, J. M., Crystal Growth & Design 2016. Download paper. The molecular structure of the units that get incorporated into the nuclei of the crystalline phase and sustain their growth is a fundamental issue in the pathway from a supersaturated solution to the formation of crystals. Using a fluorescent dye we have recorded the variation of the pH value in time along a…

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Diffusion and Precipitation Processes in Iron-Based Silica Gardens

Diffusion and Precipitation Processes in Iron-Based Silica Gardens

Glaab, F.; Rieder, J.; Garcia-Ruiz, J. M.; Kunz, W.; Kellermeier, M., Physical Chemistry Chemical Physics 2016. Download paper. Silica gardens are tubular structures that form along the interface of multivalent metal salts and alkaline solutions of sodium silicate, driven by a complex interplay of osmotic and buoyant forces together with chemical reaction. They display peculiar plant-like morphologies and thus can be considered as one of the few examples for the spontaneous biomimetic self-ordering of purely…

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A Global Scale Scenario for Prebiotic Chemistry: Silica-Based Self-Assembled Mineral Structures and Formamide

A Global Scale Scenario for Prebiotic Chemistry: Silica-Based Self-Assembled Mineral Structures and Formamide

Saladino, R.; Botta, G.; Bizzarri, B. M.; Di Mauro, E.; Garcia Ruiz, J. M., Biochemistry 2016, 55 (19), 2806-2811. Download paper. The pathway from simple abiotically made organic compounds to the molecular bricks of life, as we know it, is unknown. The most efficient geological abiotic route to organic compounds results from the aqueous dissolution of olivine, a reaction known as serpentinization (Sleep, N.H., et al. (2004) Proc. Natl. Acad. Sci. USA 101, 12818–12822). In…

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Growth Behavior of Monohydrocalcite (CaCO3·H2O) in Silica-Rich Alkaline Solution

Growth Behavior of Monohydrocalcite (CaCO3·H2O) in Silica-Rich Alkaline Solution

Zhang, G.; Delgado-López, J. M.; Choquesillo-Lazarte, D.; García-Ruiz, J. M., Crystal Growth & Design 2015, 15 (2), 564-572. Download paper. Monohydrocalcite (CaCO3·H2O) has been crystallized in silica-rich alkaline water solution. The crystallization proceeds by a counterdiffusion method without the presence of any other additive except dissolved silica. The crystallization has been followed in situ by optical microscopy and Raman microspectroscopy, while the time evolution of the pH and the concentration of calcium and silica species…

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