stillbeatsurname:Opalized wood from Virgin Valley, Nevada.The layered opalized wood structure (brown
stillbeatsurname:Opalized wood from Virgin Valley, Nevada.The layered opalized wood structure (brown) contains “easter eggs” (3-5 mm) of fire opal that are open-space fillings of pipe-like vessels (seen in cross section) known as xylem that serve as avenues of water transport from roots to leaves. -- source link