When this water is later evaporated, the copper combines with aluminum and phosphorus to deposit tiny amounts of turquoise on the walls of subsurface fractures
Turquoise formation often occurs in areas with hydrothermal activity, where hot water or fluids rich in Minerals circulate through the Earth's crust. These hydrothermal fluids carry dissolved elements and minerals, including copper, aluminum, phosphates, and other trace elements. The hydrothermal fluids interact with pre-existing rocks, such as igneous Rocks (e.g., volcanic rocks) or sedimentary rocks (e.g., limestone, sandstone). The rocks act as a host for the mineralization process. The specific composition and characteristics of the host Rock can influence the color, matrix patterns, and overall quality of the turquoise.
As the hydrothermal fluids permeate the host rock, Chemical reactions occur between the dissolved minerals and the surrounding rock materials. The presence of Copper is particularly crucial in the formation of turquoise. Copper ions combine with aluminum, phosphates, and hydroxyl ions in the fluid, resulting in the formation of the Turquoise mineral. Under suitable conditions, the chemical reactions lead to the deposition or precipitation of the turquoise mineral within the host rock. Turquoise can fill fractures, cavities, or porous spaces in the rock, forming veins or nodules. Over time, the accumulation of turquoise minerals can create solid formations.
After the initial deposition, subsequent geological processes, such as weathering and oxidation, can alter the appearance and color of turquoise. Interaction with atmospheric Oxygen and groundwater can cause changes in the chemical composition and color of the stone. These processes can result in the characteristic blue and green hues of turquoise. Turquoise is rarely found in well-formed crystals. Instead it is usually an aggregate of microcrystals. When the microcrystals are packed closely together, the turquoise has a lower porosity, greater durability, and polishes to a higher luster. This luster falls short of being "vitreous" or "glassy." Instead many people describe it as "waxy" or "subvitreous."
Turquoise forms best in an arid climate, and that determines the geography of turquoise sources. Most of the world's turquoise rough is currently produced in the southwestern United States, China, Chile, Egypt, Iran, and Mexico. Turquoise occurs as a fillung in veins or crevices, or in the form of nuggets. The most well known deposits are in the USA, Mexico, Israel, Iran, Afghanistan and China. The most beautiful turquoises, in a splendid light blue, come from deposits in the north of Iran.
In these areas, rainfall infiltrates downward through soil and rock, dissolving small amounts of copper. When this water is later evaporated, the copper combines with Aluminum and phosphorus to deposit tiny amounts of turquoise on the walls of subsurface fractures. Turquoise can also replace the rock in contact with these waters. If the replacement is complete, a solid mass of turquoise will be formed. When the replacement is less complete, the host rock will appear as a "matrix" within the turquoise. The matrix can form a "spider web," "patchy" design, or other pattern within the stone.
Matrix refers to the pattern or web-like design seen within turquoise stones. The matrix is formed by the surrounding host rock material that becomes part of the turquoise deposit. The matrix can vary in color, texture, and composition, giving each turquoise Stone a unique appearance. Turquoise deposits can be associated with specific geological structures, such as faults, folds, or volcanic vents. These structures can create pathways for hydrothermal fluids and mineralization, increasing the chances of turquoise formation within the vicinity.
Turquoise is typically found as veins, nodules, or replacements within a host rock. The host rock can vary and may include various types of rocks, such as igneous rocks (e.g., volcanic rocks like basalt or rhyolite) or sedimentary rocks (e.g., limestone, sandstone). The host rock provides the framework and structure for the formation and occurrence of turquoise. Turquoise formation is often associated with hydrothermal activity. In areas with hydrothermal systems, hot water or fluids rich in minerals circulate through fractures and permeable zones within the host rock. This hydrothermal activity plays a crucial role in the deposition of minerals, including turquoise.
Turquoise can occur as veins or fillings within fractures or cavities in the host rock. These fractures may have formed due to tectonic forces or other geological processes. Turquoise can fill these open spaces over time, resulting in the formation of vein-like structures. Turquoise mines may exhibit alteration zones where the host rock has undergone significant chemical changes due to hydrothermal activity. These alteration zones can be characterized by the presence of various minerals associated with the formation of turquoise. The alteration can result in the formation of different minerals and the creation of favorable conditions for turquoise deposition.
