What type of rock is zircon found in?
Zircon is widespread as an accessory mineral in felsic igneous rocks. It also occurs in metamorphic rocks and, fairly often, in detrital deposits. It occurs in beach sands in many parts of the world, particularly Australia, India, Brazil, and Florida, and is a common heavy mineral in sedimentary rocks.
What does a zircon rock look like?
Zircon is usually reddish brown, but can be white, orange, yellow, yellowish brown, purplish red, light red, blue, green and sometimes colourless. It is usually translucent but can be transparent.
Is zircon found in igneous rocks?
Volcanic rocks are usually finely grained or glassy in structure. Basalt is an extrusive rock, finely grained due to its rapid cooling. It largely consists of tiny feldspar and pyroxene crystals (like diopside and enstatite). Some basalts contain gemstones like corundum, zircon and garnets.
How do you identify a mineral zircon?
Natural Zircon with good color and transparency is uncommon; most Zircon crystals are opaque and brownish. However, most Zircon gemstones, especially the blue and white forms, are enhanced by heat treatment. Zircon often contains traces of radioactive elements in its structure, which causes it to be metamict.
What are zircon stones?
Zircon (Jarkan stone in Hindi) is a natural, semi-precious gemstone of the Nesosilicates mineral family that is found in different colour varieties such as white (colourless) blue, yellow, red, orange, green etc. The colourless variety is often recommended as the astrological substitute of the diamond.
Where does zircon stones come from?
Zircon is found all over the world, but gem-quality crystals are rare. Sri Lanka and Southeast Asia are the primary sources of gem-quality zircons. Sri Lanka produces material in all colors in gravels, including rare cat’s eyes. Cambodia is the chief source of material that heat treats to colorless and blue.
How is zircon stone formed?
Originally formed by crystallization from a magma or in metamorphic rocks, zircons are so durable and resistant to chemical attack that they rarely go away. They may survive many geologic events, which can be recorded in rings of additional zircon that grow around the original crystal like tree rings.
How can you tell how old a zircon is?
Another option is to dissolve the zircon grain in hydrofluoric acid to separate the uranium and the lead. The scientists can then analyze them on a mass spectrometer to get the Pb/U ratio and thus calculate the age of the zircon.
How zircon is formed?
Where are zircon crystals found?
Gem-grade zircon has been produced from alluvial deposits in Sri Lanka, Cambodia, Myanmar, and Vietnam for hundreds of years. More recent gem-grade deposits are in Australia, Nigeria, and Madagascar. Deposits mined for gem-grade zircon must contain crystals at least several millimeters in size with good clarity.