SEMSEYITE
SEMSEYITE Semseyite – Pb9Sb8S21 – is a very rare sulfosalt, typical of complex polymetallic Ag-Cu-Pb-Sb ores. It is classified in the Plagionite Group, in the Semseyite Series, composed of Pb-Sb sulfides. It may contain Fe, Ag, and Cu. 1. Characteristics Crystal system: Monoclinic prismatic. Color: Gray to black, may show some tarnishing. Habit: Tabular, prismatic, […]
SERANDITE
SERANDITE Serandite – NaMn2+2Si3O8(OH) – is a very rare inosilicate that occurs in extremely specific parageneses. It is not an ore mineral, but well-formed specimens command high prices in the collector’s mineral market. It belongs to the Wollastonite Group, within the Pectolite-Serandite series, forming a series with pectolite (NaCa₂Si₃O₈(OH)). It is the Na-analogue of tanohataite […]
SCORODITE
SCORODITE Scorodite – Fe3+AsO4.2H2O – is a relatively common arsenate, a typical alteration product of arsenic-containing minerals. It is not an ore. It is classified in the Variscite Group, being dimorphic with parascorodite and the Fe analog of mansfieldite and yanomamite. It forms one series with yanomamite, another series with mansfieldite, and a third series […]
SENARMONTITE
SENARMONTITE Senarmontite – Sb2O3 – is a rare oxide, typically a product of alteration of Sb minerals. It is found in Sb ores, where it can even occur frequently, but always in small quantities, never as the main ore mineral. The compound (Sb2O3) is commercially known as “antimony trioxide” and is obtained by melting stibnite, […]
SYLVANITE
SYLVANITE Sylvanite – (Au,Ag)2Te4 – is a rare telluride, but one of the few Au ores besides native gold and calaverite. Thus, it is a secondary ore of Au and Te. As it contains some Ag, it is also a minor Ag ore. In addition, it may contain Pb, Cu, Sb, and Ni. Due to […]
STEPHANITE
STEPHANITE Stephanite – Ag5SbS4 – is a less common sulfosalt that occurs in small quantities in many Ag mining districts, constituting Ag ore. French authors use the name proposed by F.S. Beudant, “psaturose” (from the Greek = brittle). As with all silver minerals, stephaite crystals are originally bright and have a strong metallic luster, but […]
STRONTIANITE
STRONTIANITE Strontianite – SrCO3 – is a rare carbonate that forms an important Sr ore, such as celestine. It is classified in the Aragonite Group, constituting the Sr analogue of aragonite and witherite. Sr can be replaced by Ca (up to 27%) or Ba (up to 3.3%). There is a Ca-rich variety (“emmonite”). Strontianite is […]
SELIGMANNITE
SELIGMANNITE Seligmannite – PbCuAsS3 – is a very rare sulfosalt, characteristic of polymetallic hydrothermal veins. It is part of polymetallic ores, but is never the main ore mineral in the deposit. It is probably much more common than imagined, being systematically confused with bournonite. It is classified in the Bournonite Group, in the Bournonite-Seligmanite Series, […]
STANNITE
STANNITE Stannnite – Cu2FeSnS4 – is a relatively common sulfide. It is part of polymetallic ores, being primarily an ore of Sn (27.61% by weight), but also of Cu (29.56% by weight). It is sometimes called “bell metal ore” because it was used to obtain Sn for bell casting. It is classified in the Stannnite […]
SAFFLORITE
SAFFLORITE Safflorite – CoAs2 – is a rare arsenide that is part of Co ores. It is classified in the Löllingite Group, which consists of quite rare minerals. Pure safflorite practically never occurs; there is always an appreciable content of Fe and/or Ni replacing the Co, which is necessary for the stabilization of the structure. […]