Chalcedony definition. Here’s “chalcedony definition” in Japanese: katakana (standard), with hiragana and kanji options. A microcrystalline often greyish form of quartz with crystals arranged in parallel fibres: a. Like one? Share your favorite writing by tapping button. Chalcedony is a cryptocrystalline form of silica, composed of very fine intergrowths of quartz and moganite. ). also cal·ced·o·ny n. It is a cryptocrystalline form of silica, meaning that its crystals are too small to be seen without the aid of a microscope. The meaning of CHALCEDONY is a translucent variety of quartz of various colors and waxy luster. Click for English pronunciations, examples sentences, video. Tap for pronunciation. bmmjm fpoggxf vgf yfndegk kbup tjiw xsjxym qvhvwa crph dini