Stele

Steles are the tools used by Shadowhunters to draw runes onto their skin, weapons, and other materials. They are made of adamas and crafted by the Iron Sisters.

Description
Steles look like long, slender twigs, though the length and style vary and may depend on the owner's preferences. There are many different models of steles, the appearance evolving depending on the times. Steles have a sort of aura to them, a ghostly imprint of their owner's personality. When not in use, steles are inert but they warm and glow while drawing runes.

Since steles are not designed to be used in direct battle against demons, steles do not harm them, though demons tend to recoil when exposed to a stele due to the material—the heavenly metal adamas.

Only Shadowhunters can use steles to create Marks; steles will not even produce a line when used by mundanes or Downworlders, but it will cause no harm to them.

History
The first stele is believed to have been a rough oblong of adamas used by Jonathan Shadowhunter to inscribe the first Marks on his own skin.

In About Time, Alec gives Emilia the stele specifically created for her by the Iron Sisters, after she received the Angelic rune during a special ceremony in Alicante.