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Agate

Coral

Langgan (a gemstone resembling jade)

Pungent in flavor, cold in nature, non-toxic. Originates from the country of Japan, growing among jade stones. There are three varieties: red, black, and white. Those with patterns like twisted silk are all excellent; those that do not generate heat when rubbed against wood are genuine. (If heat is generated when rubbed against wood, it is not genuine.) Locals obtain them and grind them into ornamental objects. Although regarded as precious treasures, they are also used in medical prescriptions. They can ward off evil spirits and malign influences, and are applied hot to treat redness and ulceration of the eyes. Liuli (colored glaze/glass) is a substance formed by fire; for red eyes, it can also be soaked in water and applied as a compress. Bolu (glass/crystal) is the crystal pearl, resembling jade but extremely bright and lustrous. It calms the mind and improves vision, often achieving remarkable results. Facing the Moon at night, one can obtain "true water." Using Huojing (fire crystal) to extract fire (by facing the Sun), though names differ, the essence is the same. Another type of coral grows only at the bottom of the sea. Fishing boats sink iron nets to catch them; they are reddish-brown with many branches of uneven length. Long ones may exceed one zhang, while short ones are about one chi. They have many fine pores inside, and juice flows out when pierced. When gold is thrown in, it becomes golden paste; when jade is thrown in, it becomes jade marrow. Those who drink it may attain longevity. Broken branches ground into powder can be applied to the eyes to remove film-like obstructions. Blown into the nose to treat nasal congestion and epistaxis, it calms the heart and stops fright. It also treats wind-induced epilepsy and primarily manages xiaoke (wasting-thirst syndrome). Langgan also grows at the bottom of the sea, with branches similar to coral. Sailors seeking it must use iron nets. When brought out of water, it is reddish-brown, but turns green after prolonged exposure or rotation. Striking the branches produces a metallic sound; for medicinal use, it can be boiled to make a decoction. To counteract tin toxicity, chicken bone is feared/used; it is known as Qingzhu (Green Pearl). (Ancients referred to beautiful stones as pearls, and even gold was called a pearl. The *Guangya* states that liuli and coral are both called pearls.) It is suitable to be combined with mercury. It treats skin infiltration and necrotic tissue, removes body itching, sores, and scabies. It eliminates stone lin (lithiasis) and breaks up stagnant blood, raises yin qi, and can be transformed into cinnabar. There are also shells, shaped like clams. They have many textures on the outside and also come from the sea. Those who find them treasure them, not disgracing the status of jade and stone. They calm the spirit and protect the residence, detoxify, and kill parasites. The *Records of the Western Regions* states: "The beams and pillars of grand halls and temples are all decorated with the Seven Treasures; this is one of them."