Unakite

Rock composed of green epidote, white to gray quartz, and pink feldspar; chemical composition varies with mineral content
opaque
green white to gray, and pink in a mottled pattern; may contain black veining

Identification:

Optic Character: opaque
Refractive Index: spot readings around 1.74 to 1.76, 1.55, or 1.52, depending on area tested
Birefringence: none
Pleochroism: none
Ultraviolet Fluorescence: generally inert
Absorption Spectra: not diagnostic
Cause of Color: varies with mineral content
Specific Gravity: 3.00 (+.20, -.15)
Polish Luster: greasy to vitreous
Fracture: granular to uneven
Luster: dull
Cleavage: none
Identifying Characteristics: mottled coloring, black veining
Crystal Habit: none, massive
Hardness: 6 to 7
Toughness: fair

Sources: US

Gem Reference Guide, Published by GIA. ISBN 0-87311-019-6

Gemstones of the World, Published by Sterling Publishing Co., Inc NY, ISBN 1-4027-4016-6

Encyclopedia of GEMSTONE, Published by ISHINSHA CO., LTD. ISBN 978-986-251-831-1