History & Introduction

Chrysoprase is the birthstone for the month of May and even Gemini astro sign. The name 'chrysoprase' comes from the Greek words, 'chrusos' and 'prason', which means 'gold' and 'leek', respectively; referring to its leek-green color and the presence of golden color it is a unique gemstone with a quality variety of chalcedony quartz which is a form of cryptocrystalline of silicon dioxide. Due to its opalescent minty, chrysoprase is highly prized, apple-green color that is totally a different color and is owed to its distinctive coloring agent. Most green gemstones are color of iron (tourmaline), chromium (emerald) or vanadium (tsavorite garnet), however it is seen that chrysoprase from its alluring color of nickel impurities that creates within otherwise colorless quartz crystal. Chrysoprase is among the rarest and most valuable varieties of chalcedony quartz and it is second only to the rare green-blue gem silica, which is also known as 'chrysocolla chalcedony'.

Chrysoprase from time to time occurs in quartz veins of nickel-bearing serpentine rocks and in weathered deposits of nickel ore materials. Chrysoprase, like the different kinds of cryptocrystalline quartz, is composed with crystals, which are very fine to be seen as fine particles also under magnification. Not like the chalcedony quartz, which are prized for their patterns showing multi-color chrysoprase is looked-for for its solid and intense green color that is suggestive in case of the finest quality jade.

Recognise - Chrysoprase is easily recognized through its chalcedony quartz properties and by its distinct light-green to apple-green color. It is much softer and less translucent that makes it easily differentiate from chrysoprase. Prehnite carries a similar color, however naturally it is typically not nearly as vivid or intense as chrysoprase. Variscite also create confusion, but its luster is waxier and it's knowingly softer than chrysoprase. Chrysoprase can even be discerned by distinct traces of nickel. In fact, the only other green gem color by nickel is gaspeite; all other green gems are color by iron, chromium or vanadium.

Availability - Chrysoprase deposits are available in different locations across the globe. Some of the most important sources include Australia, India, Brazil, Germany, Russia, South Africa, Tanzania, Poland, Zimbabwe, Madagascar, Kazakhstan and the United States (Arizona, Oregon and California). Previously, the mines of Frankenstein (Zabkowice) in Upper Silesia, Poland were the place where large deposits of gem quality of chrysoprase were found, however now Australia produces nearly 85% of the world's supply. Chrysoprase is mined from Central Queensland (Australia) is quality wise world's best gemstone, with different types showing translucency and color similar to that of fine quality jade.

Usages - Mainly this gemstone is used as a minor gemstone and is cut into cabochons, mainly found in oval used in pendants and rings.

Buying Guide

Chrysoprase comes from the family of quartz, however, specifically talking it is a variety of chalcedony quartz. Quartz and moganite are very closely related silicates, however they do have little bit varying crystal formations. Chrome chalcedony is also often confused with chrysoprase due to color similarities, however chrysoprase with the help of nickel is colored, whereas chrome chalcedony is colored by chromium.

Color - Chrysoprase color ranges from light, minty-green to intense deep, apple-green color. Deeper colors are considered more demanding, however, once the color comes to a certain depth, the stone may be classified as 'prase', which is not as needed as chrysoprase. Chrysoprase color can weaken under exposure to heat or direct light for a longer period, but in many cases, the color may be restored after absorption of moisture.

Clarity and Lustre - The feature of Chrysoprase is from translucent to opaque. Valuable specimens are the Specimens that are translucent are considered most valuable. As the stone is cut and polished, it possess vitreous to waxed luster. Mainly the chrysoprase creates a very clean, but an uneven, cloudy distribution of color.

Cut and Shape - Naturally the Chrysoprase is cut en cabochon and is also very popular for gemstone carvings, that adds up to cameos, ornamental objects, seals, intaglios and insignia. The most common shapes that are popular are round, hearts, ovals, trillions, and pears. Chrysoprase beads as well as tumbled stones are also popular, however these will typically be fashioned from lower grade materials.

Treatment - Most chrysoprase today is not treated. Still imitations such as dyed green agate, maybe 'misadvertised' as chrysoprase.

Gemological Characteristics:

Chemical Formula	SiO2 (with a high level of nickel impurities)
Color	Green, apple-green
Hardness	7
Crystal System	Hexagonal
Refractive Index	1.54 - 1.55
SG	2.63 - 2.65
Transparency	Translucent to nearly opaque
Double Refraction	.009
Lustre	Vitreous to waxy
Cleavage	None
Mineral Class	Quartz (Chalcedony)

Classification:

• Green Chrysoprase