Zinnwaldite is a mineral that belongs to the mica group. It is composed of potassium, iron, aluminum, silicon, and hydroxide ions. The word is pronounced /ˈzɪn.wɔːl.daɪt/ in IPA phonetic transcription, with the stress on the first syllable (/ˈzɪn/). The spelling of the word is derived from the location in which the mineral was first discovered, the Zinnwald/Cínovec deposit on the border between Germany and the Czech Republic. The suffix "-ite" is added to indicate that it is a mineral.
Zinnwaldite is a mineral that belongs to the mica group of phyllosilicates. It is a complex potassium, sodium, lithium, iron, aluminum, and silicate mineral with a composition that is rich in the element lithium. The mineral is named after its type locality, Zinnwald (now Cinovec) in the Erzgebirge mountains of Germany, where it was first discovered.
Zinnwaldite typically occurs in granitic pegmatites, which are coarse-grained igneous rocks that form from slow cooling of magma. It is commonly found alongside other lithium-rich minerals such as lepidolite and spodumene. Its color varies from brown to reddish-brown, and it often exhibits a pearly or vitreous luster.
In terms of its physical properties, zinnwaldite has a monoclinic crystal structure characterized by thin, platy layers. It has a relatively low hardness of 2.5-3 on the Mohs scale and a specific gravity ranging from 2.8 to 3.1. The mineral typically forms tabular or prismatic crystals that can grow several centimeters in size.
Zinnwaldite possesses significant economic importance due to its lithium content, which is used in various industrial applications. It is primarily mined for its lithium and aluminum ores, which are used in the production of ceramics, glasses, and batteries. Additionally, zinnwaldite is also valued as a collector's mineral, and it is occasionally faceted into gemstones for use in jewelry.
The word "zinnwaldite" is derived from its locality of discovery, Zinnwald, a historic mining town in the Erzgebirge mountain range on the border of Germany and the Czech Republic. The name "Zinnwald" itself is German and translates to "tin forest", referring to the rich tin deposits found in the area. The suffix "-ite" in mineralogy is commonly used to indicate that the name corresponds to a mineral species. Therefore, "zinnwaldite" refers to the specific mineral found in the Zinnwald region.