Your Daily Jewels: agate

Captivating Geodes Filled With Sparkling Druzy...

The first time I saw a piece of druzy jewelry, I knew I was in it for the long run. I am mesmerized by druzy. The beauty of it, and the science of it. The thought that I am holding or wearing something that has been millions of years in the making just fascinates me. There is no material I enjoy working with more. Druzy popularity has skyrocketed in recent years and it has really become a gemstone in its own genre.

How these sparkling sugary crystals come about is a mystery to many. So I will try to explain as simply as i can.

Remember this ?(this is the only chart, I promise)

The constant moving of the earth’s crust and inner layers is responsible for the forming of most of the colored gemstones we see today. Many millions of years ago, as molten rock was being forced up to the surface, heat and pressure changes caused gases to expand and create cavities within the solidifying rock. Gazzillions of years later, as the ground water, rich with minerals, (i.e. dissolved silica) moved through the rock, it deposited new minerals into the cavities, (or on the surfaces) of the rock, and cooling began to occur. Crystallization of these minerals on top of and inside the previously crystallized rock began the unique crystal formation called Druzy. Druzy colors are based on the particular stone that the mineral water leaked into all those years ago.

In the following photo you can see some of the filled cavities and you can see the tightly-packed matrix which creates a dense bed of individual crystals. Notice how each each crystal only has a single termination pyramid exposed. This bed of crystals has a very fine crystalline structure similar to sugar or salt crystals. This is an "encrustation" crystal habit, or Druzy. This is why it is so sparkly. That pyramid catches light from every which way.

Naturally Occurring Druzy Crystals

There is a wide variety of minerals that can form into druzy. Many of these examples of druzy encrustation are found all over the earth, and their colors listed below represent untreated crystals, unless noted otherwise.

Agate Drusy: Brown (Brazil)
Quartz: clear, white, tan, golden (citrine), and light purple (amethyst)
Black Garnet, Psilomelane: Black (Western Australia)
Carnelian Drusy (Chalcedony): Orangy-Yellow, Reddish-Brown (Brazil)
Chalcedony Drusy: Blue, Lavender (Brazil)
Chrysacolla: Greenish-Blue (Australia, Chili, New Mexico USA, Zaire)
Cobalto Calcite, Cobaltoan Dolomite: Pink, Rose (DRC Congo, Zaire)
Hemimorphite Drusy: Greenish-Blue (Yunnan Province, China)
Jasper Drusy: Brownish-Red (Madagascar)
Onyx Drusy (Agate): Black (Brazil) *may be dyed
Psilomelane Drusy: Indigo Blue (New Mexico USA)
Rainbow Hematite Drusy: Rainbow, Brownish-Green (Brazil) *very rare
Rainbow Pyrite: Rainbow (Volga River, Russia)
Uvarovite Garnet: Forest Green (Ural Mountains, Russia)

Enhancements:

Vapor-coating (aka vapor-deposition) is one of the more common gemstone enhancements used to achieve the scintillation and myriad of colors and that are found in druzy quartz jewelry.

Titanium is used to create intense, permanent hues of blue, green, and purple, as well as adding an iridescent (schiller effect) quality and/or play-of-color

Druzy crystal can also be vapor-coated with a variety of other metals to create interesting optical effects. Gold is used to create golden druzy, Platinum is used to create pure white, or silver druzy, and silicone oxide is used to create vibrant pink and green hues.

Some countries have taken to straight out dying druzy. Dyed druzy will fade, unlike vapor coated druzy.

Example of Dyed Druzy

Grading:

Druzy gemstones are graded using the following criteria---color saturation, crystal size, purity (visual flaws), and crystal coverage (whether areas of underlying matrix shows). The highest grade Druzy is not always the prettiest. These earrings would not be considered high grade because of the large crystals, but I think they are lovely!