Comparison of the crystallographic structure of semi nacre and nacre by electron backscatter diffraction
Comparison of the crystallographic structure of semi nacre and nacre by electron backscatter diffraction
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电子背散射衍射法比较半珍珠质和珍珠质的晶体结构
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
A. Pérez
中科院分区：
文献类型：
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作者：
Jennifer England;M. Cusack;Paul Dalbeck;A. Pérez
文石珍珠岩通常存在于软体动物的壳中，而半珍珠岩则存在于两门生物的壳中：腕足动物和苔藓虫。方解石半珠层和文石珠层具有相似的形态，由螺旋位错生长的片层组成。本研究采用电子背散射衍射法，比较了头足类huttoni和双壳类软体动物Mytilus edulis壳中方解石半珍珠石的结晶学特征。半珠质和珠质在形态上相似，但最终具有不同的晶体结构。在N. huttoni方解石半珍珠层中，c轴平行于壳的次级层的层状。相比之下，M. edulis文石珠层的c轴垂直于纹层。胡托尼鱿鱼第二层方解石半珍珠层的晶体结构与苔藓虫产生的骨骼超微结构的晶体结构相似，而与其他腕足类动物的晶体结构不同。
Aragonite nacre is commonly found in the shells of molluscs, while semi nacre has been observed in the shells of organisms from two phyla: the Brachiopoda and the Bryozoa. Calcite semi nacre and aragonite nacre display similar morphologies with laminae composed of tablets that grow by screw dislocation. This study uses electron backscatter diffraction to compare the crystallography of calcite semi nacre from the shell of the Craniid brachiopod Novocrania huttoni with aragonite nacre from the shell of the bivalve mollusc Mytilus edulis. Semi nacre and nacre are similar in morphology but ultimately have different crystallography. In N. huttoni calcite semi nacre, the c-axis lies parallel to the laminae of the secondary layer of the shell. In comparison, the c-axis of aragonite nacre in M. edulis is orientated perpendicular to the laminae. The crystallography of calcite semi nacre in the secondary layer of N. huttoni is similar to the crystallography of skeletal ultrastructures produced by bryozoans, while it differs from the crystallography described in other brachiopod genera.