代写MINERALOGY TASK#:1代写Web开发

MINERALOGY

TASK#:1

Describe each mineral separately.  Note the significant optical properties of each diagnostic mineral, the size and shape of each mineral, and the alteration (if any) of each mineral.  Determine and record the percent of each mineral within the  rock. Add rows is necessary.

Mineral Name Size and Shape	%	Diagnostic Optical Properties	Description
Olivine subhedral fractured	18%	2mblue; high birefrigence	minor resorption
opaques mineral microlites	12%	black in both ppl and cpl	staining in parts; hematite
plagioclase lath shaped zoned	45%	1 yellow; low birefrigence; 2cleavages; weak zoning; Alibite twinning	Unaltered; showslight resorption
Augite small subhedral	30%	inclined extinction

Drawing/Photo

TEXTURAL DESCRIPTION (of thin section)

porphyritic texture is present, with large olivines and plagioclase phenocrysts in a fine grained groundmass. The groundmass has a glassy and black opaque groundmass of a very weak zoning

HAND SPECIMEN DESCRIPTION (if included)

ROCK HISTORY

This would have formed from a Hawaiian volcanic suite and at an intraplate location. The olivine phenocrysts crystallized first then the augite and plagioclase formed lastly. The presence of embayed olivine suggests resorption due to interaction with the melt.