C
CARNELIAN
Name: Likely from the Latin “cornum” for “the cornel (kornel) cherry,” which shares its color, or “carne” meaning “flesh”.
Description: A semitransparent to translucent variety of chalcedony, a cryptocrystalline quartz.
Variety: Chalcedony; Agate.
Chemical Composition: SiO2
Color: It gets its color from iron oxide impurities. It has a color range from pale orange and honey-yellow to deep reddish-brown and vibrant vermillion to brownish-orange. Today, the most sought-after color of ? is ?.
Treatments: Heating improves color, is stable, very common, and undetectable. Grayish chalcedony is heated to oxidize the iron content and turn it red to orange. Dyeing is also common.
Moh’s Hardness: 6.5 to 7.
Toughness: Excellent to Good.
Location Found: Brazil; India; Madagascar; USA; Uruguay.
Birthstone: July; August.
Wedding Anniversaries: 17th
Zodiac Signs: Aries; Leo; Virgo.
Chakra Associations: Sacral; Root.
Historical Associations: eloquent speech; protect the dead on their journey to the afterlife; Isis; courage; grounding; vitality; confidence; motivation; taking bold action; speaking with power; overcoming procrastination; shielding against envy, rage, and resentment; creativity; artists; performers.
Historically Used to Treat: nosebleeds; open wounds; libido; reproductive health; childbirth; lower back pain; rheumatism; arthritis; boils; skin irritations; procrastination; rage; envy; resentment.
Care: Heat may change color. Avoid harsh acids. It is attacked by hydrofluoric acid. Ultrasonic and steam cleaning are usually safe, but avoid if the stone has significant surface-reaching fractures. Warm, soapy water and a soft brush are safe. Dry with a soft cloth. Store it in a soft pouch to maintain its high polish. It can be scratched by harder stones such as diamond, ruby, and sapphire.
Imitations: Glass; Plastic; Dyed Agate.
Synthetics: No commercial synthetic carnelian exits.
CAT’S–EYE
Name: From the Greek chrysos ("golden") and beryllos ("beryl"). The specific variety is sometimes called Cymophane, from the Greek for "appearing like a wave."
AKA: Cymophane (Greek; “waving light”). Vaidooryam (Sanskrit).
Description: A variety of chrysoberyl that is often known only as “cat’s eye” in the trade. All other gemstones must include the mineral name along with “cat’s eye”.
Chemical Composition: BeAl2O4
Variety: chrysoberyl.
Color: Honey-yellow, golden-brown, yellowish-green, and lime-green. The most valued is the “Milk and Honey” which has a creamy line on a rich honey background.
Treatments: Very rarely, it may be irradiated to enhance color, but this is uncommon. Typically natural.
Moh’s Hardness: 8.5.
Toughness: Excellent to Good.
Location Found: East Africa; Brazil; India; Madagascar; Sri Lanka; Tanzania.
Birthstone: June.
Wedding Anniversaries: 18th.
Zodiac Signs: Leo; Ketu.
Chakra Associations: Solar Plexus; Third Eye.
Historical Associations: all-seeing eye; protection from the evil eye; protection from hidden enemies; preserves wealth; regain lost wealth; wards off bad luck; speed up the healing process after a long, chronic illness; clarity; protection; prosperity; gambling; enhance intuition; clear the aura; self-control; ability to stay focused on long-term goals; protection against psychic attacks and negative energy.
Historically Used to Treat: eye disorders; physical vision; cataracts; mental stability; digestion; food poisoning.
Care: Ultrasonic and steam cleaning are usually safe. Resistant to most household chemicals. Warm, soapy water and a soft brush are safe to use. Dry with a soft cloth. Store it carefully as it can scratch other stones and gold. Only diamonds, rubies, and sapphires can scratch it.
Imitations: Cat’s-Eye Glass; Fiber-optic Glass; Cat’s Eye Quartz.
Synthetics: Flux growth and Czochralski (pulling) exist and are mostly found in scientific contexts or very high-end lab jewelry.
CHALCEDONY
Name: Derived from the Latin “chalcedonius” and likely named for the ancient seaport of Chalcedon (now called Kadikoy, Turkey).
AKA: The Speaker’s Stone. The Stone of Brotherhood.
Description: In the jewelry trade the name specifically refers to a cryptocrystalline quartz that is milky blue, lavender-blue, pale gray, or white chalcedony. The term “chalcedony” is technically the species name for a massive family that includes agate, jasper, and onyx.
Chemical Composition: SiO2
Variety: Quartz.
Varieties of Chalcedony: Agate; Amethystine chalcedony; Bloodstone (Heliotrope); Carnelian (Cornelian); Chalcedony; Chrysocolla Chalcedony; Chrysocolla Gem Silica (Gem Chrysocolla, Gem Silica); Chrysocolla Quartz; Chrysoprase; Dendritic Agate (Landscape Agate); Drusy Agate/Drusy Chalcedony; Fire Agate; Iris Agate; Jasper; Milky Chalcedony; Onyx; Sard; Sardonyx; Petrified Wood.
Color: It has a wide range of colors. In the jewelry trade the name specifically refers to milky blue, lavender-blue, pale gray, or white.
Treatments: Dyeing produces a wide variety of colors; generally stable under normal conditions and is extremely common. Some colors detectable; often assumed because of unnatural color. Heat is often used on the red and orange varieties to stabilize color.
Moh’s Hardness: 6.5 to 7.
Toughness: Excellent to Good.
Location Found: Australia; Brazil; Czech Republic; Germany; Iceland; India; Italy; Mexico; Namibia; Russia; Scotland; Turkey; USA; Uruguay.
Birthstone: June; December.
Wedding Anniversaries: 18th.
Zodiac Signs: Aquarius; Cancer; Sagittarius.
Chakra Associations: Throat; Third Eye.
Historical Associations: Protection against drowning; drive away ghosts and bad spirits; speaking; speeches; promote maternal instincts; ward off nightmares and night terrors; brotherhood; a sense of community; stability in group settings; goodwill; self-reflection; honest self-perception without self-judgment; dissipate negative thoughts and emotions.
Historically Used to Treat: lactation (white; milky); glaucoma; eye pressure; sleepwalking; fevers; grief.
Care: Color may change with heat, especially if dyed. Attacked by hydrofluoric acid; nitric acid may attack dye in treated material. Ultrasonic cleaners are usually safe, but use with caution if the stone is dyed as the vibrations can sometimes cause the dye to come out. Steam cleaning is usually safe. Warm, soapy water and a soft brush are safe. Rinse thoroughly to ensure no soap residue is trapped in the microscopic pores. Store away from diamonds, which can scratch the stone.
Imitations: Glass. Plastic.
Synthetics: No commercial synthetics exist.
CHAROITE
Name: named after the Chara River in the Sakha Republic (Yakutia), Siberia, Russia, near where it was discovered. The name is also often linked to the Russian word “chary,” meaning “charms” or “enchantment”.
AKA: Stone of Transformation; Soul Stone.
Description: A rock composed of charoite, mixed with other minerals such as aegirine (black), tinaksite (yellowish-brown), and microcline feldspar (white). It is a variegated purple, lavender and white patterns and sometimes inclusion crystals of orange, gray and/or black. It has a vitreous (glassy) to pearly luster and can sometimes exhibit a shimmering effect called chatoyancy.
Composition: a complex silicate mineral (K(Ca,Na)2Si4O10(OH,F)⋅H2O).
Color: Distinctive shades of lilac, lavender, and rich violet-purple, intermixed with swirling, fibrous patterns of white, black, gray, and occasionally yellowish-brown or greenish spots. It has a vitreous (glassy) to pearly luster and can sometimes exhibit a shimmering effect called chatoyancy.
Treatments: Natural is generally untreated.
Moh’s Hardness: 5 to 6.
Location Found: Russia (Siberia, Charo River area); Sakha Republic (Yakutia).
Birthstone: December 21st to January 19th.
Wedding Anniversaries: N/A
Zodiac Signs: Capricorn; Sagittarius; Scorpio; Virgo.
Chakra Associations: all; Crown, Third Eye, Heart, Solar Plexus, Root, Soul Star, Earthstar.
Historical Associations: dispel fear of the unknown; cleansing; uplifting; radiant; aura cleansing; clear and purify energetic/etheric body of external vibrations; opening heart for deeper connection; rejuvenating; loosen attachment; meditation; revealing of path of service; purging inner negativity; protection; healing; dispelling negativity; releasing disharmonies; protection from psychic attack; transmutation of old patterns of imbalance; healing; access past life memories; release work; deeper spiritual insights; unconditional love; synchronicities in life increased; pathless path; latent inner knowledge; remove hindrances; shadow work; energetic boundaries; courage; transformation; finding beauty in unexpected places; deep emotional spiritual healing; dissolve fear and negativity; intuition enhanced; psychic abilities enhanced; cleanse aura; integrate spiritual knowledge into daily life; emotional healing; spiritual healing; integrate spiritual knowledge.
Historically Used to Treat: detoxification; liver; pancreas; nervous system; insomnia; nightmares; sleep disturbances; headaches; cramps; high blood pressure; general health.
Care: Prolonged exposure to direct sunlight may cause color fading. Avoid ultrasonic and steam cleaners. Avoid harsh chemicals. Clean with warm, soapy water and a soft cloth.
Imitations: Plastic; Resin; Dyed massive beryl; low-grade purple fluorite.
Synthetics: N/A.
CITRINE
Name: Citrine comes from the French word “citron” meaning “lemon.” In 1385, the term “citrine” was first used in reference to yellow gemstones.Chemical Composition: SiO2
Variety: quartz.
Color: Citrine is a variety of Quartz. It gets its color from iron (Fe3+). Citrine has a color range from pale yellow to brownish orange, orange-yellow to brownish/greenish, greenish-yellow. Since ancient times it has often been mistaken for topaz. Today, the most sought-after color of Citrine is a deeply saturated reddish-orange, which can include the Madeira Citrine (gold-orange to reddish-brown) and the Fire Citrine (deep red-orange). It is rare to find in nature. Most citrine on the market is a result of heat-treated amethyst or smoky quartz. In the case of amethyst heat treatment changes the iron from Fe4+ to Fe3+ turning the purple into pale yellow to brownish-orange to reddish-orange color.
Moh’s Hardness: 7.
Toughness: Good.
Location Found: Brazil, Bolivia, Spain, Madagascar, Mexico, Uruguay, Russia, France, Scotland, and the United States of America. Fire Citrine is a trade name for heat treated citrine that comes from the Linha Estefania Mine in Brazil. Madeira Citrine is a trade name for a specific color of heat treated amethyst that comes from Brazilian state Rio Grande do Sul, Madagascar, Uruguay, and Zambia.
Birthstone: November .
Wedding Anniversary: 13th.
Zodiac Signs: Scorpio, Sagittarius, Leo, and Cancer.
Chakra Association: Solar Plexus.
Historical Associations: joy; happiness; attract wealth; prosperity; money; vital energy; protects against evil thoughts; boosting confidence; clear out mental clutter; decision making; overcoming writers or creative blocks; calming; soothing tempers; increasing intelligence; success; attracting love and protection from heartache; the Sun.
Historically Used to Treat: snake venom; poisons; stimulate metabolism; soothe stomach; pancreas; balance thyroid; manage sugar levels.
Care: High heat can cause color loss. Prolonged exposure to intense, direct sunlight for extended periods can cause the color to fade. Sudden or extreme temperature change can cause fracturing. Soluble in hydrofluoric acid and ammonium fluoride; very slightly soluble in alkalis. Steam cleaning is not recommended. Ultrasonic cleaning is usually safe. Use warm, mild soapy water is and a soft brush. Dry with a soft cloth. Store in its own soft pouch so it doesn’t get scratched or scratch other softer stones.
Imitations: Glass; Plastic; Synthetic hydrothermal quartz; Synthetic sapphire; Synthetic Spinel.
Synthetics: hydrothermal; widely produced and difficult to distinguish from natural citrine without laboratory testing.
CORAL
Name: Derived from the Greek “korallion”, which likely refers to the hard skeleton of the Mediterranean red coral.
Description: An organic gemstone that was created by a living organism. It is composed of the skeletal remains of tiny marine polyps, primarily made of calcium carbonate.
Chemical Composition: CaCO3
Color: white, cream or pink, shades of red or orange, blue, purple, or light grayish violet, lavender, black, dark brown, light brownish yellow, golden.
Precious Coral: Red (Oxblood), pink (Angel Skin), orange, and white. Organic Coral: Black and Gold (composed of conchiolin rather than calcium carbonate).
Treatments:
Dyeing deepens or changes color, usually to pink or red, but any color is possible. Dye can be affected or removed by solvents and can fade under prolonged exposure to strong light. Occasional. Might be detectable by a trained gemologist.
Impregnation w/ epoxy resin or glue-like substance fills and hides cavities and fractures. Stable under normal conditions but can be damaged or destroyed by high heat and solvents. Common in low-quality material. Detectable by a trained gemologist.
Bleaching in hydrogen peroxide solution produces a “golden” color in black coral. Stable. Common. Detectable by a trained gemologist.
Moh’s Hardness: 3 to 4.
Toughness: fair to good.
Location Found: Algeria; Australia; France; Italy; Japan; Malaysia; Midway Islands; Morocco; Philippines; Spain; Taiwan; Tunisia; United States (Hawaii; black King’s coral); Mediterranean Sea and the Great Barrier Reef.
Birthstone: April (Tibetan).
Wedding Anniversaries: 35th
Zodiac Signs: Aries; Scorpio.
Chakra Associations: Heart (red, pink, white); Root (red); Sacral.
Historical Associations: imparts wisdom; ward off and shield against evil; protection against the evil eye; protect children’s health; mourning; Medusa; prevent nightmares or night terrors; life force; diplomacy; peace; peaceful mind; shielding travelers on water; fertility; easy childbirth; the Mother Goddess; connecting with the flow of the universe and the tides.
Historically Used to Treat: anemia; circulation; teething; colic; digestive distress; nightmares; night terrors; ulcers; wounds.
Care: Avoid prolonged exposure to intense heat or direct sunlight, which can cause the color to fade. Heat blackens or burns if exposed to the flame of a jeweler’s torch. Easily attacked by acids and other chemicals. Never let it touch lemon juice, vinegar, or even heavy perspiration for long periods. Never steam or ultrasonic clean. Clean with a soft, damp cloth. Store in a soft pouch away from everything else as almost every other gemstone and gold are hard enough to scratch it.
Imitations: Glass; Plastic; Bone; Dyed Bamboo Coral (a non-precious species).
Synthetics: Gilson “Synthetic” is technically a “man-made imitation” created from calcite and pigments. It lacks the natural striations found in genuine coral.