- Magnesium (Wikipedia)
Magnesium is a chemical element; it has symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic table) it occurs naturally only in combination with other elements and it almost always has an oxidation state of +2. It reacts readily with air to form a thin passivation coating of magnesium oxide that inhibits further corrosion of the metal. The free metal burns with a brilliant-white light. The metal is obtained mainly by electrolysis of magnesium salts obtained from brine. It is less dense than aluminium and is used primarily as a component in strong and lightweight alloys that contain aluminium.
- Rockhounding Saddle Mountain Washington For Petrified Wood (rockseeker.com)
Saddle Mountain, a remote and rocky ridge located in central Washington. These hills rise to 2700 feet and offer stunning views of the desert landscape and the Columbia River below. But that’s not all – the fossilized wood on these rugged hills contains a record of the area’s geological history. Petrified or opalized wood is the official gemstone of Washington, and Saddle Mountain is a treasure trove for rock enthusiasts who love agatized wood.