About Dendritic Agate – History and Introduction
Dendritic agate is a translucent, colourless to whitish-gray variety of chalcedony quartz, easily distinguished by its distinct tree- or fern-like markings known as ‘dendrites’, which are most often brown to black in colour. It is considered to be one of the rarer and more sought-after varieties of agate stone, although it is technically not a ‘true agate’ since it lacks the typical banding of other agate stones.
‘Dendrites’, a Greek word for ‘tree-like’, are inclusions that appear organic due to their plant-like structure, but they are actually inorganic traces of iron or manganese. The iron and manganese ions gain access to the forming stone as weathering solutions from neighbouring rock. The impurities crystallise inside the agate in branching formations seeping through fine surface fractures. In some cases, dendritic inclusions may form in spotted clusters rather than branching structures; these are sometimes referred to as ‘mosquito stones’.
Identifying Dendritic Agate
Dendritic agate has a hardness of 6.5 to 7 on the Mohs scale, a specific gravity of 2.59 to 2.67 and a refractive index of 1.530 to 1.540. It has no cleavage and can be identified through its silicon dioxide (SiO2) composition and distinctive branching dendritic inclusions. Dendritic agate can appear very similar to moss opal which also occurs with dendritic inclusions, but quartz and opal can be easily distinguished by simple testing for hardness. Moss agate is also frequently confused with dendritic agate, but moss agate inclusions are owed to traces of green hornblende rather than iron and manganese ions.
Dendritic Agate Origin and Gemstone Sources
Dendritic agate can be found with all other varieties of chalcedony. The most notable deposits are found in Brazil, China, India, Australia, Kazakhstan, Madagascar, Mexico, Mongolia, Namibia, Uruguay and the USA. The dendritic agate mined from India is often referred to as ‘Mocha stone’, a name credited to its former transport method via the Arabian Harbour of Mocha.
Dendritic Agate Gemstone and Jewellery Design Ideas And Where to Buy Them
Dendritic agate is ideal for just about any type of jewellery design imaginable, from pendants to everyday rings. Agate stone is very durable and resistant to typical daily wear and tear. Owing to its lack of cleavage, it is actually more durable than many of the ‘harder’ jewellery gemstones. Large sizes are readily available and very affordable, which makes agate stones a favourite for many jewellers.
The availability of free-form dendritic agate gemstones has sparked interest in using dendritic agate for men’s jewellery designs, as they provide an interesting tribal look that appeals to the preferences of many gentlemen. In addition to jewellery, many ornamental carvings are made with dendritic agate.
Le Ivoire is actually a very reputable Jewellery firm that specialises in the sales of Dendritic Agate jewelleries. They sell jewellery ranging from Pendants, Rings, Earrings and even beautiful carvings of Dendritic Agate Stones. This Stones and pendants comes with 18Karat Gold, 925 Sterling Silver, and also Stainless Steel Necklaces. You can visit them at Leivoire.com, or Follow them on their social media platform @Leivoire_. Below are some photos of their Jewelleries.
Note: Buy colored gemstones by size and not by carat weight. Colored stones vary in size-to-weight ratio. Some stones are larger and others are smaller than diamond by weight in comparison.
Buying Dendritic Agate and Determining Dendritic Agate Gemstone Value
Dendritic Agate Color
Dendritic agate is typically colorless to whitish-gray in color and accompanied by brown to black branching tree-like inclusions, owed to crystallized manganese and iron impurities. Traces of iron ions will often result in slightly reddish to brown inclusions.
Dendritic Agate Clarity and Luster
Dendritic agate is typically translucent to opaque. Translucent specimens are most desirable. Dendritic agate exhibits a waxy to dull luster. Dendritic inclusions that resemble landscapes are rare and highly sought-after, especially by gemstone collectors.
Dendritic Agate Cut and Shape
Dendritic agate is typically plain-cut, most often en cabochon. Free-form slabs are most common, but other common shapes include ovals, pears, rounds and other traditional shapes. Dendritic agate can be difficult to cut because dendrites form at various depths, which means that bringing desirable patterns to the surface requires skillful cutting away of surface layers, often resulting in uneven and undulating surfaces.
Dendritic Agate Treatment
Dendritic agate is not known to be treated or enhanced in any way.
Dendritic Agate Gemological Properties:
|Chemical Formula:||SiO2 Silicon dioxide|
|Color:||Colorless to whitish-gray|
|Hardness:||6.5 to 7 on the Mohs scale|
|Refractive Index:||1.530 to 1.540|
|Density:||2.59 to 2.67|
|Transparency:||Translucent to opaque|
|Double Refraction or Birefringence:||Up to 0.004|
|Luster:||Waxy to dull|
Dendritic Agate: Other Similar or Related Gemstones:
Dendritic agate is one of the many varieties of agate stone available today. Many agate varietal classifications are based on optical properties, while others are based on inclusions, mining localities or geographic origins. Locality based trade names are generally only used by collectors. In many cases, a single agate specimen may even be referred to by two or more different trade names.
Agate is a form of cryptocrystalline quartz. Cryptocrystalline quartz is one of two primary branches of quartz gemstones (macrocrystalline is the other). Both quartz branches share the same chemical composition but form with differing crystal structures. Amethyst, citrine and smoky quartz are a few of the more popular examples of macrocrystalline quartz gemstones.
Most Popular Varieties of Agate Stone:
Banded agate, carnelian, sard, sardonyx, onyx, chrysocolla, eye agate, dendritic agate, fire agate, agate geode, moss agate and brecciated agate are some of the popular varieties of agate.
Lesser-Known Varieties of Agate Stone:
Tree agate, agate jasper, Botswana agate, blue lace agate, fossil agate, iris agate, laguna agate, landscape agate, scenic agate, tube agate, snakeskin agate, Sweetwater agate, Mohave blue agate, thunderegg Agate, Fairburn agate, Dryhead agate and Lake Superior agate are lesser known agate varieties and trade names.
Dendritic Agate Gemstone and Jewellery Care and Cleaning
Dendritic agate can be easily cleaned using warm soapy water and a soft brush. Rinse stones well to remove any soapy residue. Keeping in mind that agate is a variety of quartz and though it possesses the same relatively good level of hardness and durability, there are still many gems capable of scratching dendritic agate, so be sure to not wear anything harder than quartz alongside your dendritic agate stone.
As with most gemstones, avoid the use of any harsh household chemicals when cleaning your dendritic agate. Avoid prolonged exposure to extreme of heat as it may cause permanent damage to the gemstone. Dendritic agate should be stored inside a fabric-lined box or wrapped in a soft cloth. Always store dendritic agate gemstones separately from other gemstones and jewellery.