Stone Mask

The Stone Mask (石仮面) is an artifact known historically by a certain Vampiric cult hidden within the Aztec Empire.

Mounted ornamentally in the Joestar family estate by George Joestar I, one Mask eventually transforms Dio Brando into a Vampire, extending his life, as well as his influence over a significant proportion of the series.

In Part II, it is revealed that the Stone Masks were designed by Kars in an attempt to grant his race the ability to withstand sunlight. However, they were "only" powerful enough to turn humans into Vampires.

Appearance
The conventional Stone Mask has the appearance of a somewhat masculine face; eyeholes sharp and somewhat slanted. It has a small mouth in either a neutral position or a slight smile; with full lips, and small fangs resting on the bottom lip. A ridge emerges from the bottom of the forehead, running vertically to the Mask's top, joining with another ridge extending into a spiral resting on the left of its forehead.

On the Mask owned by George Joestar I, on the reverse of the forehead, there are four short lines of writing in an obscure, semi-cursive script; unexplained. The Masks featured in the story also commonly exhibit cracks and other signs of wear.

Kars' modified Stone Mask has a raised depression in the middle of its forehead, in the mold of the Red Stone of Aja.

Phantom Blood
During the mid-to-late 19th century, one Stone Mask was excavated by humans; landing in the possession of George Joestar I, who mounts it on a wall in the family home.

The Mask later becomes the subject of research by Jonathan Joestar during his study as an archaeologist, who is unable to understand its purpose and only able to come up with speculative theories.

These theories attracted the morbid curiosity of Dio Brando, who believed it to have been an execution item that he could attempt to use on Jonathan. After testing it on another human, he realizes that it transforms them into Vampires.

Upon Dio's exposure, he stabs George, using his blood to activate the Mask and become a Vampire; enabling him to further torment both Jonathan and his descendants.

Battle Tendency
In Part II, a collection of Stone Masks surround the sites of the Pillar Men's slumber; both with Santana in Mexico, and with Wamuu, Esidisi and Kars in Rome.

It is revealed that Kars alone designed the Masks with the purpose of granting himself and/or his race the ability to withstand sunlight.

Kars carries a special, modified Mask, designed around the addition of the Red Stone of Aja; which he is eventually able to use.

Human to Vampire
The Stone Mask is triggered when it is touched by human blood.

It then extend tendrils of stone from its edges, piercing the wearer's skull and brain. The tendrils are meant to precisely find and trigger certain points in the brain in a fashion described as similar to acupuncture.

The wearer is then released from the constraints of human power, gaining immense strength and other abilities; simultaneously rendering the body "dead" (in a sense) or unable to contain life; including direct sunlight or the Ripple. This collection of effects designates the wearer as a Vampire.

Pillar Men to Ultimate Beings
Kars carries a modified Stone Mask which, when fitted with the Red Stone of Aja and exposed to light, has the ability to pierce a Pillar Man's skull.

In this case, the Mask unleashes a retrograde effect, in which Pillar Men are completely immune to the Sun, gain the ability to use the Ripple; and morph their bodies on a cellular level into any creature (pre-existing; and new, conceivably).

It is unknown what effects would occur if a human were to wear the Aja-enhanced Stone Mask.

Trivia

 * As one of the most famous items in the series, the Stone Mask has appeared in several games:
 * In Heritage for the Future, as part of the "Stand Crush", when one of the players has their Guard Gauge broken by the opponent, the Stone Mask briefly appears on the screen.
 * In Phantom Blood (PS2), before every match begins, the Mask gains life for a short time and its tentacles comes out, announcing the episode start.
 * It appears in All-Star Battle as the representing item for PART I arc in several trailers and Story Mode.


 * Various games in the Castlevania series have an item called Stone Mask (sometimes called Jade Mask), which, according to in-game descriptions, were used in ancent rituals; a seemingly clear reference to JoJo. Appropriately, vampires are a central element of the Castlevania universe.