Zinnwaldite

Zinnwaldite is a phyllosilicate mineral belonging to the mica group. It is a complex silicate of lithium, iron, aluminum, and potassium, often containing varying amounts of fluorine and magnesium. It typically forms in granitic pegmatites, greisens, and high-temperature hydrothermal veins. Characterized by its brownish, yellowish, or reddish-brown color, zinnwaldite exhibits perfect basal cleavage, meaning it can be easily split into thin, flexible sheets. Its presence often indicates the presence of lithium and tin deposits. Its chemical formula is a variable one reflecting the different ion substitutions, but it can be generally represented as KLiFeAl(AlSi3O10)(OH,F)2.

Zinnwaldite meaning with examples

• Geologists studying the mineral composition of the pegmatite noted the presence of zinnwaldite, which was expected due to the region's history of lithium and tin mining. The identification of zinnwaldite was crucial in determining the potential economic viability of the area for further exploration and resource extraction, providing clear markers.
• The brown, platy crystals found in the granite sample were identified as zinnwaldite through microscopic examination and chemical analysis. This discovery was significant, because the zinnwaldite presence pointed toward the existence of lithium, and related minerals and could inform further testing to map resources.
• During the hydrothermal vein mapping, the team carefully identified several minerals including the distinctive brown zinnwaldite. Understanding its environment, geologists determined the conditions of formation and could thus interpret other mineral relationships within this specific vein. The mineral acted as a marker.
• The miners, analyzing the ore sample, focused on identifying the zinnwaldite and related lithium bearing minerals. Their attention to the appearance of the ore was critical in optimizing the extraction processes as the presence of zinnwaldite indicated potential areas of higher concentration and better yields.
• The discovery of zinnwaldite within the greisen rock formation provided a key clue for mineral exploration. The zinnwaldite presence provided a geological marker, signaling the presence of associated ore deposits and was key information in directing drilling efforts.