|Colorful obsidian. Photo: Joseph Martin|
Obsidian is dense volcanic glass, usually rhyolite in composition and typically black in color. Obsidian with multicolored iridescence caused by inclusions of magnetite nanoparticles. Obsidian is often formed in rhyolite lava flows where the lava cools so fast that crystals do not have time to grow. Glass, unlike crystals, has no regular structure and therefore fractures in smooth, curved shapes. The intersections of these fractures can form edges sharper than the finest steel blades. For this reason, obsidian was used by many native cultures to make arrowheads and blades. Even today, surgeons use the knife sharp edges in operations.
|This is Rainbow obsidian from Davis Creek, Northern California.|
The four mines - Pink Lady, Lassen Creek Rainbow, Needles and Middle Fork Davis Creek - are all located within a few miles of US Hwy 395 in northeast California. Rainbow obsidian found at the Rainbow Mine and Middle Fork Davis Creek is sought after for its colorful sheen. Pink obsidian from Pink Lady, and the bundles of obsidian needles from the Needles Mine are the most popular. To make the mines even more interesting, the Needles Mine has deposits of elongated obsidian needles, think string cheese only in glass. Ample obsidian deposits assure every looker success at finding this unique glass. To find the colored obsidian it is recommended that you go on sunny days between 11 a.m. and 4 p.m., although other hours are okay, you just have to look harder.
|Spectacular rainbow obsidian blade|
(from Davis Creek, California material) Photo: Quinn Street
On the Modoc National Forest, obsidian excavation may be done under a Free Use Authorization at any of the four designated mines. Excavation is allowed at these locations only. The Free Use Authorization allows a visitor to collect a predetermined amount per year of obsidian for their own personal use.
Free Use Authorizations are available at:
- Modoc National Forest Supervisor's Office - 800 West 12th Street, Alturas, CA 96101
- Warner Mountain Ranger District Office - 385 Wallace Street, Cedarville, CA 96104
- Davis Creek Mercantile - 41942 Highway 395, Davis Creek, CA 96108
|Peppermint stripe Obsidian from Davis Creek. photo: Scott's Rock & Gem|
|Rough rainbow obsidian from Davis Creek. photo: Scott's Rock & Gem|
|This rock had marvelous stripes of rich, vibrant color. photo: Scott's Rock & Gem|
|Davis Creek Ca, Rainbow Obsidian, photo: Scott's Rock & Gem|
|The ground at Needle Hill is absolutely littered with black and mahogany obsidian cobbles.|
photo: Scott's Rock & Gem
Part I: Top Spots For Gem Hunting In The US
Part II: Top Spots For Gem Hunting In The US
What is Lake Superior Agate, and Where Can You Find It?