Saturday, May 28, 2011

Spring 2011 Biconoid Hunt

This morning the Santa Lucia Rockhounds conducted a field trip to a location in the Coast Ranges of San Luis Obispo County where Biconoids are found in abundance. We met up at the OSH parking lot in South Paso Robles at 7 AM and left caravan-style for the trek to the location to which we as a club had the permission of the ranch-owner to be there until noon today. There was a proviso that we all sign a waver and only those with a second signed copy of the waver on their person could be on the property. Having signed this at the rendezvous point we followed club president Richard Smithen to the collection site and spent the morning collecting and enjoying the beautiful scenery, gorgeous weather and interesting geology.

Our morning rendezvous

Our parked convoy below the collection site.

Hillside containing the largest and best biconoids.

Closer in view showing some of the larger Biconoids scattered about.

Even closer in view showing Chris Driesbach and Dave Murray hunting.

My little dog Tequila excitedly wanting to get involved in the action.

Jason Martines posing with a possibility.

Jason has a reputation in the club as one of the two best in the club.

Chris Driesbach found this biconoid and split it in two.

Half A

Half A

Half A

Half B

Half B

Chris Driesbach's above Biconoid is notable for several reasons: it is relatively large in size ( about 18 inches diameter), features the classic and distinctive biconoid core configuration, is filled with druzy quartz, quartz filling is stained by iron oxide, and Half B contains a stalactite-like structure.


All photos by Kim Patrick Noyes (all rights reserved)


  1. I have several of these, never knew what to call them. Thanks.

  2. Andrew, I'm glad you found this blog post useful and edifying.... I have some more of Dave's rocks for you.... big stuff!

  3. Do you all have a junior rockhound group? I was involved in one here in MIlwaukee and while there were never a lot of kids in the group, the ones who did come really enjoyed it. Allison from Geo 2