Chicken-Blood Stone

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CHEMISTRY A mixture of clay, quartz (SiO2) and cinnabar (HgS)
CRYSTALLOGRAPHY Aggregate
REFRACTIVE INDEX 1.54 to 3.2, (varies with composition)
HARDNESS 2 to 7
SPECIFIC GRAVITY Highly variable, with the components ranging from 2.6 to 8.09
CLEAVAGE None
HEAT SENSITIVE Yes

WEARABILITY* Forget It!
SPECIAL CARE INSTRUCTIONS Avoid rough handling

ENHANCEMENTS None

*Wearability is graded as Excellent, Very Good, Good, Poor, and Forget It!
For more details see the article on "Hardness and Wearability."

    Chicken-Blood stone is one of the most prized ornamental materials in China. It is considered a protection from evil and is believed to be even more powerful than jade. In Chinese tradition, the color red is symbolic of good luck. Thus the Chinese give red seals, or chicken blood stone, to bless people for events such as marriages, birthdays, promotions, and success.
    The stone gets its name for its bright red color, resembling fresh chicken blood. The stone has eight basic colors, which blend or combine in different layers: red, black, white, yellow, green, blue, gray, and purple. It is primarily used in carvings and seals. Chicken-Blood tone is found in only two localities, Changhua and Balinyouqi, China.
    Chicken-Blood stone is a fine-grained mixture of clay and quartz, with varying amounts of red cinnabar. Since both the clay and cinnabar are very soft, it has cannot be worn in jewelry and is reserved for ornamental objects. In addition, the ingrediants vary from 2 to 7 in hardness, making it a very difficult stone to work with.

Cautions

    Care need to be taken when cutting this material. Cinnabar contains mercury sulfide, (HgS,) which is highly toxic.
    Care also needs to be used when storing the material, as cinnabar tends to darken when exposed to sunlight. It is the bright red of the cinnabar that gives this material it distinct appearance and any darkening will lower its value.

    There are reported to be Chicken-Blood Stone simulants on the market, so care needs to be taken when identifying any specimen. Fortunately, the hardness and specific gravity should make for an easy separation.

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Value

    As with other ornamental objects, the value will be based primarily on artistry and workmanship. You also need to take any antique value into consideration.

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