Zircon is zirconium silicate. It can be colorless, yellow, gray, green, brown, blue, and red. It forms prisms to doublepyramid crystals, which can reach a considerable size: examples weighing up to 5½ lb (2 kg) and 10 lb (4 kg) have been found in Australia and Russia, respectively. Zircon is widespread as a minor constituent of silica-rich igneous rocks, and in metamorphic rocks. It is resistant to physical and chemical weathering, and because of its high specific gravity it concentrates in stream and river gravels, allowing it to survive in many types of rock. Zircons are thus ideal for dating rocks radio-metrically.
Zircon is a natural, magnificent, and underrated gemstone that has been worn and treasured since ancient times. some zircon material is 4.4 billion years old, making it the oldest-known mineral on Earth. It is a colorful gem with high refraction and fire. Colorless zircon is known for its luminescence and reflective flashes of multicolored light, and is often used in jewelry as a substitute for diamonds. Vibrant blue zircons are produced by heat-treating the more common brown stones. The mineral sometimes contains traces of uranium and thorium, and this natural radioactivity can disrupt the crystal structure, causing changes to color, density, RI, and double refraction.
Specification of Zircon
Chemical name Zirconium silicate | Formula ZrSiO4
Colors Reddish brown, yellow, green, blue, gray, colorless
Structure Tetragonal |
Hardness 6.5–7.5 | SG 3.9–4.7 RI 1.81–2.02 | Luster Vitreous to brilliant sheen | Streak White |
Locations Australia, Myanmar, Cambodia, Tanzania
Clear zircon resembles diamond, but the two can be distinguished: zircon exhibits double refraction, while diamond does not.
It has sometimes been used as a substitute for diamond, though it does not display quite the same play of color as a diamond. Zircon is the heaviest of any gem, readily sinking in even highly viscous liquids.
The value of a zircon gem depends largely on its color, clarity, and size. Prior to World War II, blue zircons (the most valuable color) were available from many gemstone suppliers in sizes between 15 and 25 carats; since then, stones even as large as 10 carats have become very scarce, especially in the most desirable color varieties.
Synthetic zircons have been created in laboratories, but they are only of scientific interest and are never encountered in the jewellery trade. Zircons are sometimes imitated by spinel and synthetic sapphire, but are not difficult to distinguish from them with simple tools. Zircons come in many colors, but blue is perhaps the most popular and expensive. However, almost all blue zircon is heat treated.
Varities of Zircon
Jacinth/ Hyacinth – Yellow, orange, brown, or red variety of Zircon. Jacinth and Hyacinth are historically important terms but no longer used in the gem trade in recent days.
Jargon – Colorless, pale gray, or pale yellow variety of Zircon.
Matura Diamond – Colorless Zircon is called as Matura Diamond.
Starlite – Blue gem variety of Zircon. The Blue color of Starlite is rarely natural, and is almost always heat treated.
Jewelry application of zircon
Zircon is widly used in all type of jewelry like earing, bracelets, Necklace, rings & other jewelry because it shine Bright Like a Diamond making it popular as a gemstone, as well as a diamond surrogate.
Cubic zirconia has near-identical properties to diamond in terms of brilliance, refraction, and durability, and even the most experienced jeweler can have difficulty telling them apart from diamond.