Agate rocks are characterized by fine grain and a plethora of color. Found in various types of host minerals, Agate consists mainly of chalcedony with bits of with micro granular quartz alternated in. Although agates can be found in different types of hosts, they have been found in many volcanic rocks and certain types of metamorphic rocks.
There are many types of agates such as the Mexican agate (aka the cyclops age) that has a variety of colors embedded in the chalcedony and shows a single eye. Moss agate and other forms of the dendritic variety are formed when other filaments, vegetable growth, manganese, and iron oxides are embedded in them, showing a fernlike pattern.
Enhydro agate has small inclusions of water and maybe even some air bubbles in it, while turritella agate is formed out of silicified fossil shells. Greek agate comes in a pale white to beige color and was found in Sicily in 400 BC. The Brazilian agate is characterized by layered nodules in sizeable geodes. It is often a brown tone with streaks of gray and white and looks striking when cut opposite to its layered growth axis.
One of the most popular types of this stone is the lace agate- a cryptocrystalline silica that shows a lacelike patterns that could be eyes, swirls, or zigzags. Mexico has brightly-colored, complex “crazy lace agate” while a unique “blue lace agate” has been discovered in Africa.
Available in a luminous robin’s egg blueish-green color, Amazonite is a soft granite that was formerly found in Russia yet recently high-quality crystals have been pulled from mountains in Colorado.
Amethyst is a variety of quartz that is identified by its range of purple color due to its iron impurities. As the official birthstone of February, the highest grade of Amethyst is a “Deep Siberian” hue which is primarily purple with 15-20 percent traces of blue and red.
Characterized by its illuminous inclusions of mica and Fuchsite particles, Green Aventurine is thought to be one of the luckiest quartz crystals discovered. Found in Brazil, China, Russia, and India, Green Aventurine is available in various shades of emerald.
The black species of Tourmaline is most commonly referred to as schorl, a sodium iron endmember that accounts for the majority of all tourmaline found in nature. A little known fact is that Tourmaline has pyroelectric properties that can attract and repel sizzling ashes.
Blue Aventurine is a variety of quartz characterized by illuminating inclusions of Mica or other elements that give it a glistening or shimmering effect. Its name comes from the Italian word “a ventura” meaning “by chance” when a worker in the 1700s accidentally dropped metal pieces into melting glass and the result was a stone with random iridescent sparkles. The blue aventurine gets its color from added Dumortierite.
Jasper is a type of quartz that is found all over the world, yet Brecciated jasper contains an iron compound called hematite that gives this stone a deep red color and dark spots or bands. The term “brecciated” is a widely used word in geology to signify rock comprised of broken fragments and melded together in a fine grain structure like how the earth brought together these types of fragments into a singular matrix.
Chrysocolla is a striking cyan color with various textures. It’s been questioned what its true scientific structure is, yet is believed to form by oxidizing in copper ore bodies.
Golden obsidian is a type of stone that forms when gas bubbles get trapped in a volcanic lava flow as the obsidian is forming. The beautiful golden sheen that forms is actually impurities cause from the gasses.
Green line jasper
Green line jasper is a rare type of jasper stone that was formed as an opaque microcrystalline quartz with green veins going through it. Unlike its marbled counterpart, Green line jasper is usually combined with creamy white elements or black bands and formed into beads.
Commonly found in all sorts of rocks and soils, Hematite is comprised of several iron oxides ad has the same crystal structure as corundum and ilmenite. Hematite can have a black, steel, or silver-gray color to a bright red.
Originally found near a gypsum quarry in Nova Scotia, Howlite is a borate mineral. Howlite crystals are extremely rare and are usually white, brown, or a translucent color. Howlite’s more common form is in white nodules with irregular black or grey veins running through it. Since it has a porous texture, it can be dyed to imitate other types of minerals, like turquoise because of its equally irregular patterns. Howlite has also been referred to as “white buffalo stone” or “white turquoise”.
Deriving from India and mentioned in ancient Hindu scriptures, Indian agate breaks away from its original location and travels through rivers and streams forming into a multi-colored type of chalcedony in its journey. Many people believe that it conjures good luck when worn, averts sickness, and propels good health, wealth, and happiness for the wearer.
Found predominantly in Asian art, Jade is the term for Nephrite and Jadeite, two metamorphic rocks that contain various silicate minerals. The greener the Jade the more iron is in it and it wasn’t until the late 1800’s until a French mineralogist found that it was actually two different types of stones.
Found as an aggregate of chalcedony or micro granular quartz, Jasper is a transparent impure form of silica. Commonly red, yellow, green, or brown in color, the green version with red spots known as a bloodstone is one of the original birthstones for March. It was popular in the old world, beautiful jewelry and furnishings found from archaeological digs circa 1800.
Although antique jasper is distinctly green like emerald, the term “jasper” currently identifies as an opaque quartz of practically any color deriving from minerals found in original ash or sediment.
A mineral found in the feldspar and tectosilicate categories, Labradorite has a 50-70 anorthite percentage. Like most silicates, Labradorite has a white streak and a 1.559-1.573 refractive index range. It holds a triclinic crystal system and two directions of right angle cleavage.
Regarded as a prized semi-precious gem due to its intense color, Lapis lazuli is a compact blue metamorphic rock mottled with brassy colored pyrite and white calcite. Although it has a dull luster, lazuli being the common denominator in this mixture of minerals adds a vitreous appearance.
Malachite is a green, opaque banded mineral forms in fractures and spaces deep underground where there is chemical precipitation. Rare individual crystals look like acicular prisms but atypical blocky azurite Malachite crystals may also form.
A beautiful Australian jasper that invokes the colors of a warm Western sunset, Mookaite is a sedimentary rock that was formed in the land down under when it was “jasperized” into quartz. Its colors range in shades of reds, yellows, whites, and lavenders.
Montana agate is a type of chalcedony that is thought to be formed from the silica and mineral deposits of Yellowstone Park’s volcanic ash and then deposited into the river. Montana agate is characterized by its black manganese and red iron oxides.
Believing that it was incepted through solidified moon rays, ancient Romans greatly admired Moonstone as they associated it with their lunar gods. Its name came from its visual effects of light diffraction caused by a regular succession of a layered feldspar microstructure.
Formed from extrusive igneous rock, Obsidian is a result of felsic lava cooling into volcanic glass. Found within the margins of high silica content obsidian flows, the mixture creates a high polymerization, viscous lava product with atomic diffusion to create crystal growth. This black rock is brittle and hard, so when it breaks it creates very sharp edges.
Opalite is known to cause a soothing effect when worn or looked at. Also called “Sea Opal” or “Argenon”, Opalite can appear to have a bluish tint against a dark background or take on a milky white with lavender or yellow glow against a white background. It is a manmade glass resin fused with metal to create its opalescent effect.
Named from exhibiting a combination of patterns formed from wind, water, or other color variations, Picture jasper can be found all over the world. However, specific patterns and colors are unique to their geographic origin. A cut section of Picture jasper looks like an image or landscape scene.
Comprised mostly of tiger’s eye and hawk’s eye, Pietersite is a magnificently rare reddish or dark-blue breccia aggregate characterized by streaks or swirls of orange or gold. Named after a man named Sid Pieters who first described it in the early 1960’s, Pietersite is basically the general one-word term to describe a brecciated or marbled tiger’s eye.
Natural Pink Opal is a combination of chalcedony, opal, and palygorskite that is a sustainable alternative to pink coral or conch pearls. The color exudes a soft femininity that formed when silica and water flowed into the ground together and hardened.
Combining various colors and properties of fluorite into one, Rainbow Fluorite colors can range from violet, yellow, blue, and green to grey, black, and clear. Considered one of the most popular gems in the world amongst mineral collectors, fluorite was originally found to be effective to help in steel and aluminum processing.
Rhodonite is a pink to brownish red, gray, or yellow colored manganese inosilicate that is also Massachusetts’ official gemstone. In the triclinic crystal system, Rhodonite manganese is often partly replace by calcium, iron and sometimes zinc.
In its pure form, Rhodochrosite is a striking rose-red or pink color, but matched with other chemicals can be pared down to a pale brown or pink. Since Rhodochrosite is fairly soft, it can be difficult to cut for jewelry. It is Argentina’s national gemstone (sometimes referred to as Rosinca or Inca Rose) and in 2002 was named Colorado’s official state mineral.
Exuding a soft pink to bright red hue, the color of Rose quartz comes from traces of titanium, manganese, or iron and may produce an asterism (star-like shape) in light transmission. Crystalline Rose quartz is a bit rarer and is thought to have an accentuated color due to traces of aluminum or phosphate.
Rutilated quartz is a clear quartz with strands of a titanium dioxide mineral called rutile injected into the structure of a quartz crystal. When there are large amounts of iron oxide in the rutile, it can appear to have red and gold flecks in it. When there is low iron oxide present, the needles of rutile are practically black.
Serpentine is the name used for a group of minerals that can include metals such as magnesium, nickel and/or zinc matched with aluminum, iron and/or silicon. Primary Serpentine minerals include lizardite, antigorite, and chrysotile. Like a reptile, Serpentine is usually a shade of green (but can also be black, white or yellow) and has a waxy or greasy luster.
Snowflake obsidian is exactly how it sounds- a variety of black volcanic glass with white “snowflake” like patches of cristobalite, which forms through a partial crystallization process within the glass.
Tiger eye is a chatoyant gemstone that is normally found in golden to darker reddish-brown hues and covered with a silky sheen. Usually derived from a metamorphic rock, tiger eye gets its silky appearance by quartz crystals and amphibole/limonite fibers growing parallel within the rock.
Containing both quartz and tourmaline, Tourmalinated quartz also called tourmalated quartz, is often used as a good luck charm. Black tourmaline streaks set in clear quartz is believed to be beneficial for releasing fear and grounding.
Turquoise is a bright blue-green mineral comprised of aluminum and copper hydrated phosphate. The most natural turquoise can reach a Mohs hardness of under 6, which is just a bit stronger than window glass. It has highly variable properties and shows a triclinic crystal system in X-rays.
Discovered in North Carolina’s Unakas Mountains where it got its name, Unakite stones come in a motley of green and pink. This altered granite gets its colors from green epidote and pink orthoclase feldspar set amongst a colorless quartz.
Composed of oxygen and silicon atoms in a tetrahedra framework, quartz is one of the most abundant minerals on Earth. Milky or White quartz is its most common variety, its color a reaction of tiny particles of liquid, gas, or both trapped in during the time the crystal formed.