VIVIANITE Fe3(PO4)2·8H2O (monoclinic) . Deep blue prismatic crystals Richmond County,Virginia . 藍鐵礦晶體多作長柱形，硬度２，玻璃光澤，新鮮時透明， 暴露光線久後改變為藍到綠色或黑色，主因為二價鐵氧化為三價鐵，完美的結晶罕見，時常充填 於化石的空穴內∼fossil clam or snail shells． 本礦由黃大一博士提供．
礦名來源：Named after the English mineralogist, J. G. Vivian.

著名產地∼Maryland and Colorado, USA; Russia; Ukraine and England.

經典名礦欣賞 ．2．3．4
NO.138