How to Select and Identify Healing Crystals Part Four: Luster
Sometimes we have to step outside of the metaphysical realm of healing crystals and into the geological side in order to identify a healing crystal. Websites like www.mindat.org or it's sister site www.gemdat.org can be great tools to assist us in our identification efforts. Both sites are extremely valuable with endless information and comprehensive databases of every mineral and gemstone found on this planet. They profile each crystal individually listing their traits and characteristics. On previous posts we've looked at how to determine transparency, as well as the different optical effects. Next we will explore another optical property you can use to identify your crystals referred to as luster.
The word luster comes from the Latin word lux, meaning light. Luster is the way that light interacts with the surface of a crystal, rock or mineral. It describes the way the surface of the crystal looks. Unfortunately, determining the luster of a crystal's surface is a subjective opinion. The terms we will explore are not scientific, but nonetheless useful guides that can enhance our Crystal IQ.
Metallic luster describes an opaque mineral that reflects light off its surface just as metal does. This group of minerals includes metals, like copper and gold, as well as minerals from the Sulfide group like Pyrite and the Oxide group like Hematite. Additional healing crystals you may come across with a metallic luster include Galena, Peacock Ore (Chalcopyrite or Bornite), Lodestone or Magnetite.
Adamantine describes a transparent or translucent mineral that displays extraordinary brilliance and shine. They have a very high refractive index, meaning they bend light and disperse it into a prism of colors. There are very few minerals and crystals that can be defined as having an Adamantine luster, with the most common being a diamond. Diamonds used in jewelry are cut into facets like the one pictured below. The way they are cut and polished can enhance the brilliance and shine of the diamond since light refracts from the different facets throughout the crystal creating the sparkle we are accustomed to seeing in a diamond.
The most common luster found in crystals is referred to as vitreous. This describes a glass like appearance. It occurs in transparent to translucent minerals that have a low refractive index. Common examples of vitreous healing crystals are Quartz, Aquamarine, Topaz and Fluorite.
A dull or earthy luster describes a non-reflective surface. They scatter light instead of reflect or refract it. Crystals with a dull appearance may look like mud, dirt or clay. The most common healing crystal with a dull luster is pictured below, Sandstone.
Crystals with an appearance similar to pearls are referred to as having a pearly luster. They sometimes also display iridescence. A great example of a pearly luster can be found in the healing crystal Abalone Shell.
Crystals that demonstrate a wax like appearance have a waxy luster. Often times in Facebook mineral identification groups one will ask the querent if their crystal has a waxy appearance. If they respond yes, the crystal they are describing is usually Calcite like the one pictured below. Without describing the luster as waxy, one may think they are looking at Fluorite, but we now know that Fluorite tends to have a vitreous luster. In addition to Calcite, other healing crystals that have a waxy luster include Chalcedony, Jade and Turquoise.
The term resinous luster is used to describe the appearance of a resin-like surface, chewing gum or plastic. The most common example of a healing crystal with a resinous luster is Amber.
Minerals and crystals composed of parallel fibers demonstrate a luster reminiscent of silk and are referred to as having a silky luster. The most common healing crystal with a silky luster is Selenite.
This concludes part 4 of our series! Next time you are on Facebook and responding to a post from your fellow crystal lovers in need of help identifying a crystal be sure to ask them about the luster when appropriate! Or when you are looking up your own crystals instead of just typing in green healing crystal, you can type in translucent, waxy green healing crystal, for example. You will have narrowed down the possibilities significantly just by including those two identifying words! I also encourage you to visit the two websites I listed above. They are a great source of information and have some of the most spectacular images of crystal specimens found around the world. I hope you feel that your Crystal IQ is improving everyday and are feeling more confident sharing your passion for crystals with others!
As a token of my gratitude and appreciation for all the love and positive feedback I've received from my readers I would like to extend a coupon code good for 25% off your total purchase of $25 or more. Type in LUSTER25 at checkout!
Below is an image I created to save to your Pinterest board or computer reminding you of the different types of luster, along with a picture to use as a reference guide. Until next time!
Farndon, John, and Alec Livingstone. The Practical Encyclopedia of Rocks and Minerals: How to Find, Identify and Collect the World's Most Fascinating Specimens, Featuring over 800 Colour Photographs and Artworks. N.p.: Lorenz, 2008. Print.
Guastoni, Alessandro, and Roberto Appiani. Minerals. N.p.: Firefly, 2005. Print.
Minerals.net. (n.d.). Retrieved October 24, 2017, from http://www.minerals.net/resource/property/Luster.aspx