Scavenging Fireworm - Pareurythue sp. Picture taken October 2000.
Nikon Coolpix 950 digital camera, Tiffen 10x close-up lens, full flash

This is an example of a bristleworm (aka fireworm). They come in many different colors. These are harmless scavengers not coral and clam eaters as many people think.

The bristles are made of a glass like material that can easily penetrate your skin and they are difficult to remove. The toxins released should not be harmful long term, but it maybe very painful for several hours.

Scavenging Fireworm - Pareurythue sp. Picture taken February 2004.
Nikon Coolpix 950 digital camera, Tiffen 10x close-up lens, full flash

Here is another example of a bristleworm in my tank clearly a different species and different coloring.  Most of them do have a metalic like coloration or sparkle to them.

There are thousands of different species of bristleworms. Only a handful of them are predatory and harmful to our tank inhabitants. The odds of you having a harmful one are pretty slim.