Mineralogical-Petrographical and Gemological Properties of Chalcedony Occurences of Tokat-Artova Region

The study area is located around Gümüşyurt and Bayırlı Villages in Tokat/Artova city. Permian aged amphibolite rocks are formed the basement region. In upper part of this unit Silurian aged, grey-beige color recrystallized limestone found. There mainly metamorphic units metaclastics, having metabasic origin suh as chlorideschist, glaucophaneschist, micaschist composition white, cream, beige, blackish gray colored, hard brittle, partially silicified blocks forms region.The ophiolithic from Late Jurassic to Early Cretaceous age show a wide range distrubution South area. Eocene /conglomerates Pliocene conglomerates unconformably overlaid all previous units. Chalcedony samples, mostly green color, occured small limestone. Different tones chalcedony samples can be seen different Even if dark brown grey appaer lower quality transparency, have enough make earring, necklace, ring prayer beads. According field observations, Raman spectroscopy, GemmoFtir (Fouirer Transform Infrared Spektrofotometre for Gemology), geochemical analyses standart gemologic tests, identified “Chromium Chalcedony”, colored “Common Chalcedony”.