Li-mica Tourmaline Granite - Littlejohns (#15)
 >View Microscope
 >View Object
Fact sheet
Description: 

This porphyritic granite comes from a location within Littlejohns china clay pit to the north of St Austell. Despite being collected in a working pit, this sample is relatively unaltered with only minor sericitisation of plagioclase feldspar noticeable in thin section. Tourmaline is the main mafic species and Li-mica is also present.

Littlejohns pit has been active since the 1800s and continues to supply fine clays suitable for use in paper making. Clay is mined in this area using high pressure water hoses (called monitors) and the resulting slurry is filtering to remove the remaining mica, feldspar and quartz. 

In Place
In Time
Location description: 
Littlejohn's china clay pit, St Austell, Cornwall
Accuracy:
Location precision: 
Moderate
Timescale:
Timescale: 
Permian
Ma = Millions of years ago
In Focus
Collection:
What\
Type:
Type: 
igneous
What\
Rock-forming minerals:

Rock forming mineral:

What\
Accessory minerals:

Accessory minerals:

What\