Category Archives: Jewelry

Jet

Jet

Jet

Jet is a hard gem variety of lignite (a type of coal), which is often carved or faceted, and takes a good polish. Jet has high carbon content and a layered structure. It is black to dark brown, and sometimes contains tiny inclusions of pyrite, which have a metallic luster. Jet’s name derives from the Old French jyet or jaiet after a place on the Mediterranean coast where the Romans obtained some of their jet. Jet is the fossilized wood of prehistoric trees that have been compressed over millions of years. It smells like coal when burnt. Some jet may induce electricity when rubbed, and for this reason it is sometimes known as “black amber.”

Jet was a very popular gemstone during the Victorian era when it was used as mourning jewelry. After the death of Queen Victoria’s husband, Prince Albert in 1861, Queen Victoria went into a forty year period of mourning. Jet from Whitby in northern England was used extensively. Whitby was famous at the time for the mining and crafting of jet, and this industry was responsible for most of town‘s income during that time. Jet has been used in jewelry since ancient times and was made traditionally into rosaries for monks. In medieval times, powdered jet drunk in water or wine was believed to have medicinal properties. In India, jet amulets were believed to protect the wearer against the evil eye, and Irish women traditionally burned jet to ensure the safety of their husbands when away from home.

Today jet is found in Whitby, England, Spain, France, Germany, Poland, India, Turkey, Russia, and the United States.

Jet can be confused with anthracite, asphalt, cannel coal, onyx, and schorl. Some imitations are made with glass, vulcanite and plastics.

Jadeite

Jadeite
Jadeite

There are two different minerals known as jade.  They are “nephrite,” which is an amphibole, and “jadeite,” which is a pyroxene.  Nephrite is the most common and widespread.  It is formed of a mat of tightly interlocking fibers, creating a stone tougher than steel.  It was used in China and New Zealand for tools and weapons due to its toughness.  Its color varies with its composition dark green when iron-rich; cream colored when magnesium-rich.  The term “jade” evolved from the Spanish piedra de ijada, meaning “loin stone,” a stone of similar appearance to nephrite brought from the New World by the Spanish, which was, in fact, jadeite.

There are two different textures that help distinguish nephrite from jadeite; nephrite appears fibrous or silky; jadeite commonly has a more sugary or granular texture.  It has a bright glassy shine.  Pure jadeite is white.  Its other colors include green, colored by iron; lilac, colored by manganese and iron; and pink, brown, red, blue, black, orange, and yellow, colored by inclusions of other minerals.  Emerald-green jadeite, colored by chromium, is called imperial jade.  The latest classification of jadeite jade is; “A” jade (natural untreated); “B” jade (polymer treated); “C” jade (stained); “B” & “C” jade (polymer treated and stained).

For the Indians of Mexico, Central, and South America, jadeite was a symbol of water and the burgeoning of plant life. Known as chalchihuitil, it was more precious than gold.  The Olmecs were the first Mesoamericans to discover and carved jade; perhaps 3,000 years ago. Across Mexico and Central America it was used in the most precious objects: masks, depictions of the gods, and ritual items.  A piece of jade was placed in the mouth of a deceased nobleman which was believed to serve as his or her heart in the afterlife.  Jade grave goods were essential for members of the nobility in most Mesoamerican cultures.  When powdered and mixed with herbs, jadeite was used to treat fractured skulls and fevers, and to resurrect the dying.  Mesoamerican jadeite principally came from sources in Guatemala and Costa Rica.

Myanmar is a major source of jadeite, and in particular imperial jade.  Other sources are in Japan and California.  Until the late 16th century, virtually all European jade was nephrite.  When the Spanish reached Mexico, they discovered that the Aztecs prized a green stone that was similar in appearance to, and believed to be the same stone as, European jade.  They were told by the Aztecs that this stone cured internal ailments, especially those of the liver, spleen, and kidneys.  This stone was brought back to Europe, along with the belief in its healing powers.  The jade from South America was believed to be the same as the Old World jade until 1863, when a Chinese carving was analyzed and discovered to be a different stone.  The new stone was given the name jadeite, meaning derived from jade.

Jadeite and Nephrite can often be confused with agalmatolite, amazonite, aventurine, californite, chrysoprase, hydrogrossular garnet, pectolite, plasma, prase, prehnite, serpentine, emerald, smaragdite, smithsonite, and verdite