Identification of a rock?

[JDK]

I dont know much about geology/rocks/gems. I found this rock in a river. Its about the size of a quarter black and rough with little holes that are shiny black like obsidian. Can someone tell me what it is. I will post a picture as soon as I can

 

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[JDK]

 

[DDancer]

Need a clearer picture and natural lighting. Use a soft white background Might be obsidian. Try a streak test as well.

 

[JDK]

Is this better? Also it seems heavy for such a small stone.

 

[JDK]

Crater lake is about 100 miles from where I found this.

 

[BurntBear]

Appears to be water-worn slag glass. Looks like it was worn down by ocean waters. Did you find it near the coast?

 

[JDK]

Not really I found it in the North Umpqua river in Glide Oregon

 

[BurntBear]

Could be Obsidian.

 

[rodoconnor]

What color streak does it have?

 

[DDancer]

The streak will be the color of the stone however what you'll be looking for is going to be a grainy line that looks like little bits of fractured glass. It may or may not streak on porcelain but because it does fracture easily you should see what I'm talking about.
Obsidians can be found in that part of the country. But as pointed out by BB it could be slag glass as well. Lots of bubbles in it where as most obsidians are fairly solid.

 

[hvacker]

Reminds me of basalt, basic lava. We have a lot here, blow holes and all.

 

[JDK]

Streak is dark gray dust/residue appears black

 

[hvacker]

Bubbly basalt.

 

[Rockhunter1620]

Water worn pumice, most likely.

 

[DDancer]

Yup

 

[hvacker]

JDK said it was heavy.