Long Xianxiang is dark brown like amber, sometimes with colored stripes. It is an opaque solid wax-like rubber block with a lasting fragrance and a unique sweet earth fragrance, so it is called "grey amber" in the west.
Long Xianxiang has been used as a high-grade perfume since ancient times. Long Xianxiang purchased by perfume company is graded, ground into very fine powder, dissolved in alcohol, and then mixed with 5% Long Xianxiang solution, which is used to prepare perfume or as a fixative (perfume which can make the fragrance of essence more stable and volatilize slowly is an important part of essence). Therefore, Long Xianxiang is very expensive, almost equivalent to gold.
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Most of the Long Xianxiang found are secretions from the intestines of sperm whales. After encountering irritating foreign bodies (such as the coracoid bones of squid and octopus), the oil and secretions in whale intestines will wrap the foreign bodies, and other organic substances will be decomposed by biological acids and microorganisms, and will be excreted with the digestive system or after vomiting. Then after a long oxidation process in seawater, they will naturally saponify when they meet salt and alkali in the ocean, forming a dry solid perfume.
Long Xianxiang discharged into the sea is light black at first, then gradually turns gray, light gray and finally white under the action of seawater. Among them, white Long Xianxiang has the best quality. It must be soaked in seawater for 100 years, and all impurities will come out before it can become the top grade in Long Xianxiang. Long Xianxiang taken from the intestines of a killed sperm whale is of no value. It has to float and soak in seawater for decades (Long Xianxiang is lighter than water and won't sink) before it can gain lofty status.
The above contents refer to Baidu Encyclopedia-Long Xianxiang.