The Seven Treasures of Buddhism: An Update
After the first few inclusions to Phos, fans speculated that he would eventually contain all 7 of the jewels in his body. As the series continued and Phos continued to fight for the Lunarians many including myself speculated that just like the seedless lotus pod, Phos was meant as a deconstruction of Japanese Pure Land Buddhism. Ichikawa would set Phos up to obtain all 7 jewels only to fail in doing so. So now that chapter 99 has been published let us review the status of Phos' components.
From scouring the internet there's a few different lists of which 7 jewels are counted but here's a summary of what I have found.
tridacna/fossilized shell
a red/pink jewel (carnelian, coral, etc)
(1) glass sometimes replaces either pearl or lapis lazuli
gold: on the beach of beginnings Phos takes on a gold and platinum alloy to replace his missing arms.
silver: Phos' new arms contain platinum, and after Phos' final fight against Cinnabar, he takes on some of Cinnabar's mercury giving himself a skin. Both platinum and mercury are silvery metals.
shell: Phos' new legs are made of Aculeatus' shell which has a core of agate and an outer layer of shell. An agatized fossil shell.
agate: Phos' new legs include agate
lapis lazuli: Phos' head is replaced with the head of Lapis Lazuli by Cairngorm.
pearl: Aechemea implants an artificial pearl eye into Phos.
adamant: Phos receives Adamant's eye. Kongo (金剛) can be translated a number of ways. It refers to vajra or a ritual weapon of absolute hardness/strength and power, diamond, adamantine a mythological unbreakable material.
I remember there was some speculation way back when that the carnelian/red-pink gem would be from Padparadscha since the word means lotus (pink) colored, but it seems Ichikawa has chosen another path. Just from reading the English articles one might think that kongo in the sense of diamond would be the crystal or glass mentioned below because all are clear and colorless, but I doubt this. The term both the Japanese and Chinese Wikipedia articles use is "玻璃" which is glass while crystal at least in the modern language would be "水晶", however only the Japanese article links to the page for quartz (石英). Kongo (金剛) however is a completely different concept referring to the mythological weapon/material.
What to make of this? I don't know I feel like I need an advanced degree on the history of Buddhism in Asia, a Buddhist theology/philosophy degree, and fluency in like 4 languages (Japanese, Chinese, Pali, Sanskrit). Perhaps much like Phos has broken from the path of the 7 Gems of Buddhism, lifeforms on the planet have too broken away from humanity. Maybe Japanese Pure Land Buddhism is a broken philosophy and we should all ditch it.
Wikitionary: gold, silver, crystal, tridacna (clam shell), agate, amber, coral
Chinese Wikipedia page on the 7 Treasures:
"Buddha Says Amitabha Sutra": gold, silver, agate, clam shell, lapis lazuli (2), glass, carnelian.
"Infinite Life Sutra": gold, silver, agate, clam shell, lapis lazuli(2), glass, coral.
"Lotus Sutra": gold, silver, agate, clam shell, lapis lazuli(2), pearl, rose colored stone.
The Japanese Wikepedia page on the 7 treasures:
"Infinite Life Sutra": Gold, silver, lapis lazuli, glass, clam shell, coral, agate.
"The Lotus Sutra": gold, silver, agate, lapis lazuli, clam shell, pearl, rose colored stone
Chinese Buddhism Encyclopedia: gold, silver, lapis lazuli, seashell, agate, pearl, and carnelian.
Nichiren Buddhism Library: gold, silver, lapis lazuli, seashell, agate, pearl, and carnelian
(2):琉璃 translated by google as "colored glaze" refers historically (and religiously) to a blue jewel like lapis lazuli imported from the cultures west of China, it is a Pali loan word from the Sanskrit word vaiḍūrya (which actually refers to cat's eye stones). It was later sometimes replaced with a blue man-made object with a glassy surface such as colored glass, ceramic, or cobalt glass. The modern term refers to colored glass sculptures as compared to 玻璃 which is the general term for glass, like a car window.