Rare Antiquities & Ancient Artifacts

The Grape Agate gemstone is a relatively new find, 2017, from Indonesia. Although the common name is Grape Agate, these are really Botryoidal Purple Chalcedony. Botryoidal means that round tiny sphere-shaped crystals that have naturally formed together. 

Chalcedony is not scientifically its own mineral species, but rather a form of Quartz in microcrystalline form. It is a form of silica, composed of very fine intergrowths of quartz and moganite.

Chalcedony appears in numerous ways. It sometimes occurs in geodes, lining the cavity with small round blobs. Its agate variety is also found in geodes, commonly lining the outer layer underneath the larger quartz crystals. Chalcedony also forms pseudomorphs after organic material.

A well-known, and most common example is petrified wood, in which the wood has been completely transformed into various colors of chalcedony. In the Petrified Forest National Monument in Arizona, an entire forest was transformed into petrified wood. What is left of the forest can be seen in the myriad of agatized trees.

For most of time, chalcedony was thought to be a ‘fibrous’ variety of cryptocrystalline quartz, but more recently, it was actually discovered to be a combination of quartz and another silicate mineral; moganite (a polymorph of quartz). Both quartz and moganite share the same silicon dioxide (SiO₂) chemical composition, but they have varying crystal structures. Moganite is monoclinic, while traditional quartz belongs to the trigonal crystal system. Chalcedony forms with a hexagonal crystal structure. 

As the defining mineral for 7 on the Mohs scale, it is a rather hard mineral and is good for jewelry. The actual name ‘chalcedony’ originated from the latin word ‘Chalcedonius’, which is thought to be derived from ‘Chalcedon’, an ancient seaport of Asia Minor, now Kadikoy, Turkey. 

A common form of chalcedony is compact silica most often found in sedimentary and volcanic environments. Formation occurs over a long period of time, as minerals are slowly deposited into a pocket of another type of rock, such as granite. The most abundant chalcedonic deposits are in areas that host volcanic rock . In many cases, silicon dioxide forms in sometimes readily visible and parallel bands, as seen in banded agate.

Many semi-precious gemstones are in fact forms of chalcedony, although in the gem trade, the name chalcedony usually describes only white or blue chalcedony. 

The more notable varieties of chalcedony are: Agate, Iris Agate, Binghamite, Bloodstone, Carnelian, Chrome-Chalcedony, Chrysocolla Chalcedony, Chrysoprase, Jasper, Dallasite, Orbicular Jasper, Onyx, Sardonyx, Petrified Wood, and Pietersite. Petrified wood is one of the most common forms of chalcedony.

Metaphysical Properties

Grape Agate is a tranquil and gentle stone. It promotes inner stability, composure, and maturity. It’s warm, protective properties encourage security and self-confidence. It allows for deep and intense levels of meditation in a short period of time. Grape Agate is a crystal of dreams, intuition, and luxury. It is a healing crystal of the crown chakra.

Purple Chalcedony acts as a psychic stimulator and protector, as well as a caller of visions and dreams. Both Purple and Blue Chalcedony activate the third eye chakras, but Purple Chalcedony’s frequency accesses the deepest levels of the subconscious, bringing long-hidden blockages, memories, or patterns into consciousness. It is a powerful stone for journeying consciously through the dream state.