अकैन्थाइटः
अर्जेंन्टाइट सदृश परन्तु पतले प्रिज्मीय क्रिस्टलों में मिलनेवाला एक सिल्वर सल्फाइड खनिज (Ag2S)। इसका रंग लोहे जैसा काला होता है।
विकिपीडिया से (Meaning from Wikipedia)
Acanthite, Ag2S, crystallizes in the monoclinic system and is the stable form of silver sulfide below 173 °C. Argentite is the stable form above that temperature. As argentite cools below that temperature its cubic form is distorted to the monoclinic form of acanthite. Below 173 °C acanthite forms directly.[1][4] Acanthite is the only stable form in normal air temperature.
