Banded flint : 3D documentation

This type of flint is found in the Upper Jurrasic settlements of Świętokrzyskie Mountains. The most important exploration points and outcrops of this raw material are found on the northeastern Permo-Mesozoic ridge, in the strip running from Iłża to Zawichost (Król and Migaszewski 2009: 19; por. Krajcarz et al., 2014). Banded flint was described for the first time by Stefan Krukowski (1939). It occurs in Jurassic limestone at various depths or in its weatherings. This regards above all the concretions or paralel layers. The size of concretions varies, the largest specimens reaching even a diameter of 2 m. But the average size oscillates between few and several centimeters. Large specimens have polycentric structure whereas smaller ones have simple structure, with core placed centrally. Banded flint is characterized by irregular splitting ability, resulting from varying hardness of singular bands in flint mass. Scar surfaces vary from smooth to lightly rough or uneven. Transparency is very low and only by the edges. Characteristic trait of this raw material is the presence of lightgrey, grey and dark grey bands arranged mostly concentrically, irregularly and alternantly (reminding onion-skin; Balcer 1975: 54; Migaszewski et al., 2006; Król and Migaszewski 2009: 21; Bąbel 2015)该类燧石（flint）发现于波兰圣十字山脉（Świętokrzyskie Mountains）的上侏罗统（Upper Jurassic）聚落遗址中。该燧石原料最重要的勘探点与露头分布于东北侧的二叠-中生代隆起带（Permo-Mesozoic ridge），即从伊尔扎（Iłża）至扎维霍斯特（Zawichost）的条带区域（Król与Migaszewski，2009：19；可对比Krajcarz等人，2014）。条带状燧石（banded flint）由斯特凡·克鲁科夫斯基（Stefan Krukowski）于1939年首次进行描述。它赋存于侏罗系灰岩的不同深度或其风化层中，主要涉及结核体或平行层。结核体的尺寸差异较大，最大标本直径可达2米，而平均尺寸则在数厘米至数十厘米之间浮动。大型结核体具有多中心结构，小型结核体则为简单的中心核结构。条带状燧石的特征之一是其不规则的劈裂性能，这源于燧石块体中各条带硬度的差异。其剥片疤痕面从光滑至轻微粗糙或凹凸不平均有分布。其透明度极低，仅在边缘处略有透光。该原料的典型特征为浅灰色、灰色与深灰色条带，多以同心状、不规则状交替排列，状如洋葱表皮（Balcer，1975：54；Migaszewski等人，2006；Król与Migaszewski，2009：21；Bąbel，2015）