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。该原料的关键勘探点与露头（outcrops）主要分布于东北侧的二叠-中生代隆起带，即从伊尔扎（Iłża）至扎维霍斯特（Zawichost）的条带区域（Król与Migaszewski，2009：19；可参照Krajcarz等，2014）。条带状燧石最早由Stefan Krukowski于1939年正式描述。该类燧石赋存于侏罗系灰岩中，赋存深度不一，或见于其风化层内，尤其富集于结核与平行层中。结核尺寸差异极大，最大标本直径可达2米，而平均尺寸仅为数厘米至数十厘米。大型结核具有多中心结构，小型结核则结构简单，核部位于中心位置。条带状燧石的核心特征为劈裂性能不均一，这源于燧石团块内各条带的硬度差异。其断口面形态各异，从光滑至轻微粗糙或凹凸不平均有分布。透明度极低，仅在边缘处可观察到。该原料的典型特征为：浅灰、灰色与深灰色条带多以同心状、不规则状交替排列，外观类似洋葱皮（Balcer，1975：54；Migaszewski等，2006；Król与Migaszewski，2009：21；Bąbel，2015）