well...it depends on what part of the country or world you are living in....if you are outside the united states, i have no idea. i assume yo are within the u.s. so most likely, the snake you are inquiring about is a type of rat snake. they actually vary somewhat in color, so without a pic, noone can be sure.
diamondback rattlesnakes also have diamonds on their back. they are usually a browner color but i can only assume anyone would recognize the rattles on any rattlesnake.
you may look up a pictorial directory for snakes in your area by preforming a search on Google or Yahoo.
There are several different types of snakes that can be black with white or gray diamonds on them. The possibilities include a California king snake or a black rat snake. Both are non poisonous.
Black Snake Diamond Röle was created in 1981.
The snake you are describing is likely a diamondback water snake. These snakes are non-venomous and are commonly found in freshwater areas across North America. Their brown bodies with black diamond-shaped markings and silver bellies are distinctive features.
if it has a diamond shape head it is poisonous
what does a white snake with black diamonds on the back mean
That is the endangered Georgia Tube snake.
it lives in North America that's where the diamond black rattle snake lives.
Lots of snakes are brown and black. You'd need to be more specific about the patterning, size, head shape, and location you spotted the snake to get a good answer.
king cobra
Are you saying that the snake has like a "hood" around the head? If so, that is a cobra.
Depending on where you live, there can be many types of snakes with these similar patterns. The most common types would be certain kinds of Garter snakes or juvinile Black Racers. Rattlesnakes can also have this type of pattern.
black snake
It depends on the snake. They can be blue, to brown, to black, to red. They can be solid or have very complex patterns. You should post a more specific question if you're asking about a certain type of snake.