Manansala tells about how these clay jars were sacred among south east asians, Taiwanese, Chinese and the Japanese and that it may have been because the clay was deemed precious and that it had special healing qualities:
Jars have a long history of sacred and medicinal use in the region of the Philippines and Borneo.
To the present-day, heirloom jars, some massive in size, continue to have spiritual and prestige value among indigenous peoples in the region.
When the Sultan of Brunei was offered the equivalent of $100,000 to part with his sacred jar, he said that no offer would be sufficient. Water from the jar was believed to have special magical properties and visiting farmers from as far as the Bisayas in the Philippines were said to have come to obtain a little magic water for their fields.
For the Japanese, the Luzon jar was important because it was the only vessel capable of storing high-quality tea to their liking. From various reports, the jars also appeared to have been viewed as having medicinal and spiritual properties.
…the Japanese had an old mythological tradition of jar worship going back to the epics Kojiki and Nihon Shoki. Jars were associated with food production even before rice agriculture, something that may hearken back to Jomon times. The jar sacrifices and festivals were instituted by Jimmu and linked with the far-off fairyland Takamagahara.
Evidence that the Luzon jars, used in the tea ceremony (chanoyu) since at least the early Muromachi period (1334—1467), were considered sacred may first appear, in European sources at least, in the notices of Carletti during the 1590s.
In describing the Luzon jars in Japan, Carletti noted that “the king of this Japan and all the other princes of the region have an infinite number of these vases, which they regard as their principal treasures, esteeming them more than anything else of value.”
Referring to tea or cha, Carletti has this to say about their relationship with the Luzon jars.
But to return to the aforesaid cha, besides the many special properties that they attribute to it, they say that the older the leaf the better it is. But they have great difficulty in preserving it for a long period and keeping it in prime condition, as they do not find containers, not even of gold or silver or other metals, which are good for this purpose. It seems a superstition, and yet it is true, that cha is preserved well only in the aforesaid vessels made simply of a clay that has this virtue…
Carletti notes that the Japanese consideration of the old and homely Luzon jars seemed beyond reason and linked with some superstitious or supernatural belief in the clay used to make the vessels.
(See more info More on Luzon Jars by Paul Kekai Manansala) ]
These Luzon clay jars were not only considered sacred but were so valued that they were of high value and even further embelished with gold:
“Rusun (“Luzon”) Sukezaemon’s story is well-known in Japan. The Sakai merchant brought back 50 Luzon jars and sold them to agents of the Shogun. He became fabulously rich and built a mansion that put the local castles to shame.
That the Luzon jars were made in Luzon is quite clear from the Tokiko, a work on the Namban, or Southern, ceramics trade.
The Luzon jars are marked as Rusun-tsukuru “made in Luzon” and all the jars from the south are manufactured with “Namban clay.” Shogun Hideyoshi had a tsubo or pot purposely manufactured in Luzon during his reign.
… Some examples of these holy jars have been found in Japanese collections. One piece brought from Japan to the Ethnographical Museum matches quite perfectly the description provided by de Morga. It is of brownish color earthenware and small in size. De Morga says of the clay pots purchased by the Japanese that they “overlay them externally with fine gold embossed with great skill, and enclose them in cases of brocade.”
In a similar way, maybe to compensate for their unsightly appearance, the Sultan of Brunei’s talking jar was “generally enveloped in gold brocade.”
The Ethnographical Museum piece was said to be made of composite pieces welded together with the joints, apparently at a latter time, overlayed with gold.
The Luzon clay jars were distinguished with symbols marked on them:
Luzon pots, according to the Tokiko, were marked with symbols that relate to the native scripts of the Philippines, and jars with these markings have been found in archaeological works.”
Those from the Bizen kiln had this mark.
And that one of the markings was one that looked like the letter T and in baybayin is actually the LA:
…the tea-canisters from the Bizen kiln made of Rusun clay had this mark repeated three times
The Tokiko says these markings are in the Rusun-no kokuji “the national writing of Luzon.” Indeed, the symbols for Luzon clay do resemble characters in the baybayin script. These include the characters for LA in Kapampangan, Tagalog, Bisayan and Ilokano, the NA character in Kapampangan and Tagbanua, and the KA character in Tagbanua.
In addition, these characters also resemble the symbology that we mentioned before. I stated that the rokuro spiral would represent the dragon clan, while the “T” symbols used for Rusun clay, would stand for the cosmic tree and by implication the bird clan.
Read more at Land of Sacred Jars by Paul Kekai Manansala.
In his reference to the “T” or baybayin LA symbol, he believes it stands for the cosmic tree and also the bird clan. Manansala believes the Cosmic Tree of Life plays a significant cosmological meaning in pre-historic south east asian history;
Also known as the world tree, tree of life, tree of death, tree of enlightenment/knowledge, tree of speech, tree of heaven, etc.
Often considered the center of the earth, the cosmic tree is said to protrude form the top of the cosmic mountain or from the ‘navel of the world.’
Read more by Manansala at Glossary: Cosmic Tree.
And has published two books available online at amazon.com:
Quests of the Dragon and Bird Clan (book version of the blog) and
Sailing the Black Current: Secret History of Ancient Philippine Argonauts in Southeast Asia, the Pacific and Beyond.