Red Diamond
D492022277ce96d68fc7cf70b5223237f9cc2f62 159175 870 1249
First Appearance: Ch. 64
Status: unknown
Race: Gem
Age: Unknown
Hardness: 10
Family: Kongo-sensei
Teammate: unknown

Red Diamond is the first of the Gems to be discovered by Kongo-sensei.


Red Diamond has a red color scheme and is depicted as wearing a white dress that resembles an oversized shirt. Their hair is cut in a medium bob.


Red Diamond is shown to be a very cheerful and curious gem. They often acted like a child.


  • They were found by Kongo-sensei in the Shore of Nascency.
  • They were the first gem to be taken care of by sensei.
  • Red Diamond, along with sensei, found Fluorite.
  • They helped Kongo-sensei with carving out a living space from a large piece of quartz (currently the school the gems inhabit).
  • It is suspected that she might have been taken to the Moon like many of the Gems born after her.

Gem Info

  • Mineral: Diamond
  • Chemistry: C
  • Color: Red

Diamond (from the ancient Greek ἀδάμας – adámas, meaning "unbreakable", "proper", or "unalterable") is one of the best-known and most sought-after gemstones. Diamond is the only gem made of a single element: It is typically about 99.95 percent carbon. The other 0.05 percent can include one or more trace elements, which are atoms that aren't part of the diamond’s essential chemistry. Some trace elements can influence its color or crystal shape. The hardness of diamond and its high dispersion of light – giving the diamond its characteristic "fire" – make it useful for industrial applications and desirable as jewelry.

It forms under high temperature and pressure conditions that exist only within a specific depth range (about 100 miles) beneath the earth’s surface. Diamond’s crystal structure is isometric, which means the carbon atoms are bonded in essentially the same way in all directions.