Anderson Lake, Morgan Hill, Santa Clara County, CA.

Collecting: White, clear and blue agate. Jasper, orbicular jasper, 'poppy jasper'. Magnesite. Chromite. Jade.

For more info on this location see Site 62 in Gem Trails of Northern California by James R. Mitchell.
 
following the one way road up to the dam, park at the far end of the damn (great views from the top of the dam). It cost about $2 for parking at Anderson Lake County Park. Beyond the fence there is a trail leading down to the lake, follow the trail along the lakes edge around to the rock face where you can find jasper and agate-jasper chunks, magnesite viens are seen within the serpentine and agate veins within the chert. The bluest agate seems to be more present within the darkest red chert and jasper. Some of the chalcedony even seems to be carnelian. Rangers may kick you out if they see you with hammers and chisels, though they shouldn't give you to much trouble if you are just carrying out a couple of pieces. I believe, however, collecting is not really allowed here. I wouldn't count on finding much intersting jasper or the 'poppy jasper' the area is famous for in this area of the park.

I, luckily, am able to collect on privet property on the south east side of the lake. On this private property I find large, interesting pieces of jasper, agate-jasper and orbicular jasper though nice examples of 'poppy jasper' are hard to find anywhere in the area at this point. I have also found jade here.

White, clear and blue agate veins:

 Uncleaned, unpolished jasper collected, with permission, on private property on the south east side of the lake.

















Blue agate-jasper:

 

Jade:

Agate Beach County Park, Bolinas, Marin County, CA

Parking lot with bathrooms located at the end of Elm Rd, on Ocean pkwy. Along the beach can be collected jasper, petrified whale bone, abalone shells, jade and agate.

This location is well know for its 'oil agates'. These agates are described as being "water clear agates containing interesting, black, spot-like inclusions" (Mitchell, 144). Some believe these black spots are inclusions of oil in the agate though I have not seen any reliable sources or scientific information to back this up. At one time large golf ball sized agates could be collected here but now most agates are pea sized, with the largest being the size of a dime. I had seen one or two quarter size agates collected in late 2013. For best collecting walk along the beach as the tide is going out and focus on areas with larger accumulation of pebbles. The agates are easier to see when wet, so stick to the waters edge for easiest collecting. You can easily fill a sandwich bag with small oil agates in an hour or so here. I have seen 3"-4" pieces of petrified whale bone collected here, jade and jasper as small pebbles. Marin Counties Dept. of Parks web site currently (2014) states that the collecting of rocks, shells and any other marine life is prohibited. I have never seen this enforced...

'Oil Agates' Collected 01.01.2014 
Chalcedony, Var: Agate
Agate Beach County Park, Bolinas, Marin County, CA 













Sources:

         Mitchell, James R. Gem Trails of Northern California. Baldwin Park, CA: Gem Guides Book, 1995. Print.