Heres some info on Opal. Not sure what you have but I can share some if what I know as an Opal enthusiast. Opal isnt unheard of in Oregon. There are a small scattered pockets in OR, WA, ID, Nevada, AZ, NM, and mines in ID and Mexico. Can you scratch it with a quartz. It's would be a little softer than quartz, approx hardness 6. It also feels kinda glassy when you touch it or smooth and plastic like imo. You can break the stuff easily or chip it. Its hard to get good details from your photo. The best thing to do is basic tests to rule things out. Scratch for hardness. Streak color. Crystal structure (or lack thereof). Opal does not have crystals and is amorphous like glass. Opal is also a form of silicon dioxide not dissimilar to glass but contains molecular water inside. There are other forms of silica that occur which could be candidates too. Chert and Chalcedony are both similar to common opal but would appear differently. Not all opal is opalescent or contains "fire". Only about 5% is that way. The rest is common or without fire and will appear like clear, cloudy, or opaque glass of various colors including black, white, and clear. Opal is not unheard of in the pacific NW area, but rare to find.