Friday, July 5, 2019

MARIPOSITE - LAPIDARY WORTHY?

My Mariposite yard rock.

The green and white that make up Mariposite make it an attractive yard rock. But as they say in the television commercials, there's MORE!

WHAT'S IN A NAME?

When miners during the California Gold Rush discovered they could find gold and placer gold in the green and white rocks around them instead of standing in a cold creek with a pan, they named the rocks Mariposite for the town they were standing in. (Not a huge imagination happening here, but a great way to tell others where to find it).


It can be found in many areas around the world, where it is mostly called Mariposite, except for Canada where they call it Virginite for some reason. Now, if you want to check my research, please check for Virginite on Google. When I checked on Bing, their articles under "virginite" were not about rocks. Nuf said.

WHAT IS MARIPOSITE?

It's actually not a mineral. Depending on how you want to think about it, it's either a metamorphic rock or a conglomerate. Chromium-rich Mica give the rock its green color and its flash. Dolomite Marble or Quartz provide the matrix. 

Mariposite slab



CAN I CAB IT?

 That depends on your willingness to handle disappointment. First, let's examine the hardness on the Mohs scale of the mineral which compromise the rock

Mica       2.5-3 
Dolomitic Marble  3.5-4
Quartz  7

As you can see, the Mica and Marble are similar in hardness, but soft as heck. If you want to cab it, plan on making it into a pendant where the edges are encased or it won't last long.  When the Mica is next to Quartz, undercutting is a real problem. 

I decided to create some Mariposite flowers for this blog post. Not my best idea ever. You can see that  I got one (of several tried) flowers. The plan was to make three and make a divot in the center that would hold a crushed yellow rock/epoxy mix to make it look like a flower. 

Flower start in Mariposite 


The first one came out fine. A bit rustic, but that was what I was looking for.  The others, even though I was using 220 grit and higher, shattered. Apparently, this rock is known for, basically, falling apart. I plan to try to get some more done so I can make a flower arrangement, but I think I'll need to drop them on the floor first to see where the slab breaks naturally.

OTHER USES

Aside from gold mining and cabs, Mariposite has traditionally been used for other practical purposes including being a facing stone for buildings or fireplaces and even markers in cemeteries (although I suspect they weathered so quickly that their messages were soon lost).

Have you worked with Mariposite?  What was your reaction?

Until next time, your Lapidary Whisperer,

Donna








 

No comments:

Post a Comment