Amorphous calcium carbonate (ACC) plays a crucial role in the formation of biogenic carbonates. It is widely accepted that ACC and organic macromolecules alter the fracture properties of Echinoderm calcite from the well‐defined cleavage planes of the raw material to conchoidal. However, the influence of ACC on the outstanding macromechanical properties of Echinoderm calcite is unknown. To address this question, full‐grown spines of the slate pencil urchin are shortly heated to 250 °C. Differential scanning calorimetry indicates that all ACC is crystallized at this temperature. Heated spines are compared with an untreated control group and no significant differences in compressive strength, bending strength, damage tolerance, and Young's modulus are detected. This highlights the weak influence of ≈6 wt% ACC on the macromechanical properties of Echinoderm calcite, which are likely established by its intricate and damage tolerant microstructure. When heating Echinoderm calcite, organics decompose, Mg calcite transforms, water is lost, and cracks and micropores form. All these processes are analyzed to exclude their influence on the mechanical properties, and it is imperative to consider them all. Only this way meaningful results can be achieved as these processes are temperature and dwelling time dependent and may even occur below 250 °C.

中文翻译：

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非晶态碳酸钙与海胆刺宏观力学性能的关系

非晶态碳酸钙（ACC）在生物碳酸盐的形成中起着至关重要的作用。人们普遍认为，ACC和有机大分子可将棘皮方解石的断裂特性从原料的明确裂解面改变为贝壳状。但是，ACC对棘手方解石出色的宏观力学性能的影响尚不清楚。为了解决这个问题，将成年的板岩笔型海胆刺骨加热至250°C。差示扫描量热法表明所有ACC在该温度下结晶。将加热的刺与未治疗的对照组进行比较，未发现抗压强度，弯曲强度，损伤耐受性和杨氏模量有显着差异。这凸显了≈6wt％的ACC对棘手方解石的宏观力学性能的微弱影响，这可能是由于其复杂且耐损伤的微观结构所致。加热棘皮动物方解石时，有机物分解，方解镁变质，水分流失，形成裂纹和微孔。分析所有这些过程以排除它们对机械性能的影响，因此必须将它们全部考虑在内。只有这样，才能获得有意义的结果，因为这些过程取决于温度和停留时间，甚至可能在250°C以下发生。分析所有这些过程以排除它们对机械性能的影响，因此必须将它们全部考虑在内。只有这样，才能获得有意义的结果，因为这些过程取决于温度和停留时间，甚至可能在250°C以下发生。分析所有这些过程以排除它们对机械性能的影响，因此必须将它们全部考虑在内。只有这样，才能获得有意义的结果，因为这些过程取决于温度和停留时间，甚至可能在250°C以下发生。