is an opaque black Iron-rich variety of Sphalerite.
is named from the German
word marmatit, from the
occurance at the Marmato Mining District, Mun. de Salamina, Caldas Department, Colombia.
This occurance is located about 50 km NNW of Manizales
and has been worked for Gold since the middle of the 15th century.
Marmatite is occassionally available as mineral specimens
but rarely available as a faceted gem. Specimens
or gems are very attractive with adamantine to metallic
luster and a refractive index of 2.369 which is almost
as high as Diamond at
for finding Marmatite: Nandan County, Hechi Prefecture, Guangxi Zhuang Autonomous Region, China;
St Christoph Mine, Breitenbrunn, Breitenbrunn District, Erzgebirge, Saxony, Germany;
Ludmilla Mine, Nagybörzsöny (Deutsch Pilsen; Deutschpilsen), Börzsöny Mtns, Pest County, Hungary;
Bottino Mine, Stazzema, Apuan Alps, Lucca Province, Tuscany, Italy;
Trepca complex, Trepca valley, Kosovska Mitrovica, District of Kosovska Mitrovica, Kosovo;
Naica, Mun. de Saucillo, Chihuahua, Mexico; Ojuela Mine, Mapimí, Mun. de Mapimí, Durango, Mexico;
Huanzala Mine, Huallanca District, Dos de Mayo Province, Huánuco Department, Peru;
Herja Mine, Chiuzbaia (Kisbánya), Baia Mare (Nagybánya), Maramures County, Romania;
Cavnic Mine (Kapnikbánya), Cavnic (Kapnic; Kapnik), Maramures County, Romania;
Turt Mine (Ghezuri Mine), Turt, Negresti-Oas, Oas Mts, Satu Mare, Satu Mare County, Romania;
Lola Mine, El Pino, El Gorguel, Sierra Minera de Cartagena-La Unión, Cartagena, Murcia, Spain;
San Valentín Mine (San Valentín Open pit), Sancti Spiritu, Sierra Minera de Cartagena-La Unión, La Unión, Murcia, Spain;
Jose Maestre tunnel, Portman, La Unión, Sierra de Cartagena, Murcia, Spain;
Smallcleugh Mine, Nenthead, Alston Moor District, North Pennines, North and Western Region (Cumberland), Cumbria, England, UK;
Eagle Mine (New Jersey
Zinc Eagle Mine; Gilman Mine; Wilkesbarre shaft; Newhouse tunnel; Little
Chief Mine; Iron Mask Mine; Belden Mine; Black Iron Mine), Gilman,
Gilman District (Battle Mountain District; Red Cliff District), Eagle
County, Colorado, USA.