Emperor Huizong reigned supreme from 1100 to 1126 Emperor Huizong abdicated His throne to his son. He was known for his promotion of Taoism and talents in poetry, painting, calligraphy and music. The Jin armies were closing in and eventually took over his Northern Song Empire and he was captured 1127 and he died in captivity in 1135, from the wealthiest man in the world to a broken man. His vast collections were gather up and stored in large wooden crates and passed down through the centuries. Since China has opened up in the 90s many old collections have reached the market place. My Imperial Ru ware collection comes from Huizong's personal collection.
During Emperor Huizong reign he decided to commission the Ru Kiln to produce wares for himself and his court because they were giving the finest Imperial tribute wares to him out of all the kilns. The Ru Kiln Imperial tribute wares that were given to Emperor Huizong was the finest wares the Ru Kiln was producing at that time, they don't have flaws and to make them really special they used several colors and added fire gilded bands on the rim and sometimes the base also. (Fire gilding with gold and mercury, the mercury metal being driven off afterward by fire. This type of gilding hasn't been used since the mid 1800 because it's very dangerous ) on the rim and sometimes the base also. All tribute wares have the fire gilded bands that are around the rim and base and sometimes only the rim. These bands have extensive layered cuprite and malachite corrosion that only occurs in nature and can't be faked. (From the book Copper and bronze in art by David Scott)
(chapter 3 page 106 Malachite in bronze patinas) The natural transition of metal to cuprite to malachite is very difficult to replicate in the
laboratory. In fact, most of the recipes for producing artificial green patinas on copper alloys, such as those compiled by Hughes and Rowe (1982), do not result in malachite formation over a cuprite layer. Consequently, the existence of this type of corrosion, supported by analytical and metallographic studies, is a good indication of the authenticity of an artifact.) This started some of the other kilns to add fire gilded bands on their Imperial tribute wares also.
Before the Ru Kiln was the actual Emperor's Official Royal Imperial kiln they were producing wares that were quite small and have sporadic crackle and were fired on stilts leaving spur marks on the base. None of these wares have crushed agate in the glaze and often these wares had flaws. The severely flawed wares were destroyed, the wares that had severe firing flaws were sold to the population for a very cheap price, These are the same wares that are being sold by Sotheby's and Christie's, and often found in Museums that have Ru ware collections. The better wares were sold to the wealthy merchants and were quite expensive. The finest wares were given as tribute to the Emperor Huizong, he had been receiving all these flamboyant wares from all the kilns. Emperor Huizong decided to commission the Ru Kiln and make them the first official Royal Imperial Kiln in China, to create wares that would be the 1st Official Royal Imperial wares used exclusively for himself and his court in China's history. He wanted the wares to look similar to wares from past history they had to be Celadon color and look like they were carved from jade similar color to the Koryo wares from Korea. He didn't want the wares to have spur marks after he saw the prototypes, they started firing the wares flat in the kiln with unglazed foot rings. Emperor Huizong wanted them to use Rare Blue Crushed Agate in the glaze, crushed agate has only been used in Official Royal Imperial Ru wares that were developed by Emperor Huizong. The 1st commissioned wares the biscuit has a grayish color that turns brown after firing some of the wares have marks scratched in the base most say Feng Hua among other marks, and they all have a cracked ice crackle. Rare Blue Crushed Agate has only been used in Official Royal Imperial Ru wares that were developed by Emperor Huizong. He wanted these wares to be larger than the Ru kiln tribute wares and very modest with simplistic refined forms often they used trumpet formed mouths, All of these Royal Imperial 1st commissioned wares were used for the Emperor and his court only regardless of any flaws that occur in the firing process.
The Ru Kiln was now the official Imperial kiln and they focused on making Imperial wares only for the Emperor and his court. Emperor Huizong saw real beauty in these wares in spite of them often being flawed and simplistic because each piece had its own character like human beings he saw beauty. Eventually some of his Imperial advisors wanted more beautiful wares, so Emperor Huizong decided also to have the Ru Kiln produce the finest Celadon wares China has ever produce for himself and the court. The 2nd Official Royal Imperial wares Huizong commissioned are not modest they are very elegant, luxurious and beautiful with very rich glaze and the finest Celadon wares China has ever produced. These wares are all celadon in color with different tones and they also used Rare Blue Crushed Agate in the glaze in all these wares. They have very rich celadon glaze and crushed Blue agate was included and there is no crackle in the glaze except for silver banded wares have a few lines, the forms are very exquisite, the foot rings are unglazed they were fired flat in the kiln, the biscuit is off white and turns brownish after firing, they sometimes used fire gilded copper bands on the rim and base on some special wares, they also used silver bands on the rim only on special wares that used a darkest celadon glaze these have a few lines of crackle. All 2nd commissioned official Royal imperial wares are not marked.
All the Ru Ware that was produced before they became the official Royal Imperial kiln doesn't have agate in the glaze. All the Auction houses and Museums claim they used crushed agate in the glaze in all the Ru ware they have recorded and the say it can't be seen because it melted in the firing process, this is a totally false narrative. All the Ru ware they have recorded is not the official Imperial Ru ware that Emperor Huizong commissioned the Ru Kiln to produce for him and his court its all flawed Merchant wares. Agate melts at 1600C to 2600C degrees and the Song dynasty kilns temperature only reached 1250C degrees at best, so this is a fallacy that the crushed agate melted in the glaze, They never used agate in any merchant wares also it would be very difficult to crush agate into a complete powder this is why you can clearly see traces of the agate in the glaze using a 20x loupe or better in all official Royal Imperial commissioned Ru Wares.
I've collected this hoard of Ru/Ju wares and these wares have been hidden away since the fall on the Northern Song Dynasty and the Qianlong Emperor did not have the ability to collect such pieces, the pieces he collected were from flawed pieces that were sold to the population and the wealthy merchant class pieces the Ru Kiln was producing before they became the Official Royal Imperial Kiln. The merchant Wares that were collected by the Qianlong Emperor during the Qing Dynasty are all that was known to exist at that time. Until collectors from the 20th century started collecting mostly flawed population Ru ware. Since the 1990s China has opened up to the world and many fine pieces and collection that were hidden have reached the market place. I realize this will clear up some of the questions about the Ru/Ju Kiln wares and Emperor Huizong reign. For many years everyone had to rely on the pieces that are from the Qianlong Emperor's collection, those pieces are very nice but they are not the real official Royal Imperial Ru/Ju wares that Emperor Huizong commissioned the Ru/Ju Kiln to produce for himself and his court.
After the Jin Army over run the Northern Song Dynasty The Imperial Royal Kiln workers fled to the South and half of the worker went to work at the Imperial Guan Kilns and the other half went to work for the Longquan Kiln, which you can see how the Longquan pieces resemble the famous 2nd commissioned Royal Ru Kiln Wares. But the Longguan wares don't have the crushed agate in the glaze.