26 DISCOVERMAGAZINE.COM
FROMTOP:^ANDREWTREMAYNE/NATIONAL^ PARK^ SERVICE;^HBO^ (2 )BY GEMMA TARLACHmore than a million years. Thanks to the
material’s unique chemical attributes,
archaeologists can determine the geo-
graphical origin of even small pieces. But
that’s only part of the story.
Arizona State University archaeologi-
cal scientist Andrew Zipkin says knowing
where our distant ancestors collected
obsidian allows researchers to ask much
broader questions, such as where early
humans traveled, and why.
“It’s easy to source obsidian and deter-
mine where it came from, but that’s only
the first step, because that’s chemistry,
not archaeology,” says Zipkin. “The
ultimate goal is to understand what
motivated these people to collect it from
that location.”GETTING TO THE POINT
Obsidian artifacts turn up at archaeo-
logical sites going back at least as far as
1.7 million years ago, when an early
member of the genus Homo made
tools with it at the Ethiopian site of
Melka Kunture.
Around the world, the prehistoric
record is littered with obsidian scrapers,
choppers and all-purpose hand axes.
Early toolmakers likely chose the
volcanic glass because it flakes predict-
ably — it can be shaped more easily than
other materials — and the result is a
razor-sharp edge.
“The fresh edge of an obsidian flake is
just a few dozen atoms thick,” says Ellery
Frahm, an archaeological scientist at Yale
University. “When viewed under a micro-
scope, a steel surgical scalpel would look
like a dull and badly abused ax next to an
obsidian flake.”
Obsidian is also brittle, a bonus for
hunters.
“An obsidian projectile point creates a
lot of damage because it’s sharp and also
likely to break inside the animal,” says
Albuquerque-based geoarchaeologist
M. Steven Shackley, professor emeritus at
the University of California, Berkeley. He
adds: “If you want to create damage, you
want to use obsidian.”
The material’s bold appearance — shiny
and usually black, though red and otherThe Real
Dragonglass
Not just the stuff of fantasy, obsidian
chronicles our deep past.
Shiny and sharp, obsidian is enjoying a bit of a pop culture
moment. It plays a central role in HBO’s hit fantasy series
Game of Thrones, now wrapping its final season. Called dragonglass
on the show, obsidian is one of only two substances that can cut
down White Walkers, malevolent otherworldly warriors.
In the real world, the volcanic glass reveals the human story in
a way no other material can.
Our evolutionary ancestors used obsidian for toolmaking forO«
ORIGIN STORY
An obsidian
projectile point
(top) from central
Alaska, backlit
by sunlight; on
HBO’s fantasy
series Game
of Thrones, the
material is used
to make weapons
(right) to fight
an undead army
(below).