Carnelian, also referred to cornelian, is a brownish-red gemstone. It is also sometimes referred to as “sard”, although sard is generally harder and darker than carnelian. Carnelian is a variety of the silica mineral chalcedony, a member of the quartz family and is colored by impurities of iron oxide. Most carnelian today is heated to enhance its reddish brown color.
Hardness: Carnelian is a fairly hard gemstone being 6-7 on the Mohs scale.
Color: Carnelian’s color ranges from yellowish-orange to reddish-brown to a deep red. The most favorable pieces are deep red or have a reddish-orange hue. Their transparency also ranges from translucent to opaque. This fine gem is often enhanced by using a heat treatment to attain a bright red to orange hue.
Birthstone: Carnelian is the Zodiac birthstone for the sign of Virgo but it has also been associated with Aries, Taurus, Cancer and Leo.
Scarcity: Natural carnelian is increasingly rare and it is important to able to identify the difference between natural carnelian and synthetic carnelian. The best way to distinguish natural carnelian is by holding it up to the light. Natural carnelian will show a cloudy distribution of color.
Source : Carnelian can be found deep inside sedimentary, igneous and metamorphic rock and is formed during volcanic eruptions. When lava explodes, these rocks retain large amounts of this chalcedony variety as rough. Carnelian was first discovered in Arabian and Egyptian deserts. Currently, India is the leading source of this captivating gemstone and Indian carnelian stones tend to be the brightest in color and rarely require enhancement. The secondary source for this stone is Madagascar. Stones from this country are famous for their reddish brown or reddish orange color. Other countries that produce Carnelian are: Brazil, Uraguay, China, Scotland, West Germany, Colombia, and Russia.
Value: Carnelian is commonly found in several parts of the world. Due to its abundance, it is an affordable gem. The value is greatly determined by the gem’s color, carat weight and where is comes from. Stones that are bright red in color hold the most value, followed by reddish orange and other colors. The higher the carat weight, the more valuable it is. India and Madagascar produce the highest quality stones and therefore are more valuable. This is the reason why the price increases if these countries furnish the buying items. Clarity and cut are not factors that greatly affect the value of a stone.
Most Common Cuts: Today, the most common cuts for carnelian are smooth oval or round. The stone is firm and sturdy and therefore easily made into any desired shape. It is not typical to find carnelians in square, marquise, emerald and other creative shapes, however. Carnelians are often used to make cabochons, beads, cameos, intaglios and sculptural pieces.
Chemical Formula: Chemically, Carnelian is composed of Silicon Dioxide, SiO2, and gets its red color from Hematite (Iron-Oxide, FeO2) impurities.
Synthetic Varieties: Today, many carnelians on the market are actually agates that have been dyed and heat-treated and are sold under different names such as red agate, red chalcedony and red quartz. Buyers who are purchasing these products need to be cautious and check out the credibility and reputation of every seller. Buyers should also inquire whether the stone is color treated or if it is natural.
History: Carnelian is one of the oldest known gemstones and holds a noteworthy history. Romans discovered that hot wax does not stick to carnelian and began using the stone in rings for imprinting a seal on letters and important documents. Carnelian is also one of the twelve gemstones denoted in the Bible as appearing on Aaron’s Breastplate. The stone continued to hold its notoriety and nobles were often buried with this gemstone. Many legends have become associated with carnelian and throughout time, it has been regarded as one of the luckiest gems to wear.
Rumored Healing Properties: The healing powers of gems remain a controversial issue but due to its long history, carnelian has developed a reputation for holding many positive qualities. It has been touted to give one courage, happiness, vitality, energy, protection from bad vibes, help one retain a good sense of humor and calm ones temper. It is said to treat depression, increase the appetite, purify the blood, relieve menstrual cramps and back pain, and treat infertility. Folklore also suggests that carnelian was used protect a traveler after death and guard against evil.