: Druzy Crystals
Druzes Crystals used in Jewelry
Source: Occuring worldwide in variant forms
Ocasionally, when amethyst, chalcedony, garnet, or similar mineral crystals grow they can form a tightly-packed matrix which creates a dense bed of individual crystals, each with only a single termination pyramid exposed. When this bed of crystals has a very fine crystalline structure similar to sugar or salt crystals, it is known as "druzes," "druzy," "drusies," or "druzi," which is described as having an "encrustation" crystal habit. This aggregate of minute crystals coating a surface is also referred to as "druzy encrustation."
Druzy Quartz and Geodes
Most druzy quartz occurs inside of chalcedony geodes which formed as nodules within ancient volcanic rocks or lava. Cavities within the rock where slowly filled by silicate and zeolitic minerals, which were deposited in layers upon the walls of the cavity. When the deposition process does not proceed to the point where the cavity is completely full, a hollow space remains causing a geode. The hollow interior of the geode can then become encrusted with a final layer of druzy crystals.
Druzy Quartz Crystal Jewelry
Druzy Encrusted Crystals
In its natural state, druzy quartz is clear, white, tan, golden (citrine), and light purple (amethyst), but there is a wide variety of dramatic colors found in jewelry-grade druzy, which is mostly the result of artificial heat and/or irradiation treatments. Druzy crystal is typically cut into flat planes (calibrated druzy) to be placed into a bezel jewelry setting.
Naturally Occurring Druzy Crystals
There is a wide variety of minerals that can form into druzes, and these naturally occurring druzy specimens occur in a variety of hues. 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)
- 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)
Druzy Quartz Color 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. This is a similar process to the application of thin films and metallic coatings onto silicon wafers, used in electronics. In a vacuum chamber, vaporized titanium metal is mixed with oxygen and deposited onto the crystal, bonding to the surface at a molecular level. Titanium is used to create intense hues of blue, green, and purple, as well as adding an iridescent (schiller effect) quality and/or play-of-color.
Uvarovite Garnet Druzy Pendant by Michale Sherman
Druzy Encrusted Crystals
Druzy crystal can also be vapor-coated with a variety of metals to create interesting optical effects. Gold is used as a vapor-coating 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.
Bibliography on Druzy
Maxam Magnata, Calibrated Drusy Gemstones . www.drusy.com