“A ffragment of a silicified sea urchin test (Echinoidea) preserved within hard, brown flint (chert), found near the Odra River in Poland. This specific specimen demonstrates ideal structural preservation due to the process of silicification. Visible on its surface are perfectly reconstructed details of four large primary tubercles (mamelons) surrounded by areoles. The entire surface between the tubercles is densely covered with fine secondary granules and small tubercles. This characteristic morphological sculpture strongly indicates its affiliation with a Jurassic genus of Cidaroid (Cidaroida), most likely Rhabdocidaris. This stone is valuable evidence of Upper Jurassic (Oxfordian) fauna which, as an erosion-resistant erratic, traveled to the Opole region. It is an ideal specimen for collectors and educational purposes. Article link: https://www.mindat.org/article.php/5396/Je%C5%BCowce+z+krzemieni+Opolszczyzny.+Metody+i+Cechy+Rozpoznawcze ”