Quartz Diorite with Laumontite Vein

Title

Quartz Diorite with Laumontite Vein

Alternative Title

Pyroxene Quartzite

Identifier

TMJ-05

Description

Rock Sample:
The sample color has a cream colored matrix with dark green phenocrysts. The sample contains Laumontite, which is a mineral in the zeolite group. There is a white talc-like substance on upper part of sample. Phenocrysts are medium to coarse grained ranging from 1~8mm in length. There are multiple fractures that span the length of the sample. Some of the fractures are filled in with a white talc-like powder. The sample has an overall rough texture.

Thin Section:
Small fractures are evident within the thin section. There are some blue minerals that have a birefringence of 0.004, that are biaxial (-). It somewhat swirls.
-Quartz (50-55%)
-Amphibole (25%)
-Augite (25%)
-Magnification at 4x/0.10

Scanning Electron Microscope:
The white talc like filling found in the fractures of the sample is made up of calcium, aluminum, silicon, and oxygen--this substance could be the Laumontite.

Date

1969

Contributor

Western Minerals, Inc.

Spatial Coverage

Tanzawa Mountains, Japan

Temporal Coverage

N/A

Accrual Method

Purchased from Western Minerals Inc.

Unit

Vein

Number of Thin Sections

1

Geolocation