Skip To Content
Go to gemstones.com homepage
Sign In
Recommended searches
Gemopedia
  • Ruby
  • Sapphire
  • Tanzanite
  • Diamond
  • Emerald
  • Opal
  • Moissanite
  • Peridot
  • All Gemstones in Gemopedia
Shop Gemstones
  • Shop Jedora Gemstones
  • Shop JTV Gemstones
Videos
  • All About Black Diamonds
  • Unboxing a Million Dollars in Gemstones!
  • Unboxing Emeralds: Gemologist vs. Geologist
  • Unboxing Rough Diamonds
  • Unboxing Garnet: Rhodolite, Pyrope, Demantoid
  • Marvel Cinematic Gemstones
  • All About Pearls and How They're Made
  • Fun Facts About Tanzanite
  • Freshwater Pearls vs. Saltwater Pearls
  • All Videos
Articles
  • Gemstone Collecting
  • Gemstone Beauty
  • Gemstone Color
  • Gemstone Origins
  • Optical Properties
  • Rare Gemstone Collecting
  • Gemstone Luster
  • Phenomenal Gemstones
  • All Articles
Showcase Collections
  • Quartz Gemstones
  • Organic Gemstones
  • American Gemstones
  • Birthstones
  • Mineral Specimens
  • Colors of Tourmaline
  • All Showcases
About Us
  • About Us
Feedback
  • Survey
Account
  • Account Information
  • Author Biography
  • Articles
  • Gemstones Home
  • Gemopedia

Sanidine

Feldspar

By Tim Matthews, JD, FGA, GG, DGA,
CEO and President of JTV (retired)
Published: June 2014
Modified: September 2023
Sanidine Polished Sanidine Rough
  • Facebook
  • Twitter
  • Copy Link
Table of Contents
  • General Information
  • Sanidine Colors
  • Countries of Origin
  • Care

Sanidine is a potassium-rich feldspar which is related to amazonite (microcline) and orthoclase by its chemistry. The name comes from the Greek sanis meaning “little plate” and idos that translates to “to see”. Specimens are not common and cutting grade material is hard to find. Carlsbad twining is common in mineral specimens. Sanidine gems that display adularescence, a mystical internal glow, are called moonstone. Colorless to yellow and pale brown gems have been found in Germany, Mexico, and Madagascar. Most larger gemstones come from Itrongay (Itrongahy), Madagascar.

General Information

  • Classification
  • Optical Properties
  • Characteristic Physical Properties
  • Chemistry & Crystallography
Common Name
Sanidine
Species
Feldspar
Transparency
Transparent - Translucent
Dispersion
Strength: Weak Fire Value: 0.012
Refractive Index
1.518-1.531
Birefringence
0.003-0.007
Optic Character
Biaxial
Optic Sign
Negative
Polariscope Reaction
Doubly Refractive (DR)
Fluorescence
SWUV: Inert to weak red-orange
LWUV: Inert to weak red-orange
Pleochroism
Unobservable
Hardness
6-6.5
Streak
White
Specific Gravity
Typical:2.600
Luster
Vitreous
Fracture
Conchoidal, Uneven
Cleavage
Perfect, in two directions
Chemical Name
Potassium or Sodium Aluminum Silicate
Chemical Formula
(K, Na)(AlSi3O8)

Crystal System
Monoclinic
Chemistry Classification
Silicate

Sanidine Colors

  • Brown Sanidine
    Brown
  • Colorless Sanidine
    Colorless
  • Yellow Sanidine
    Yellow

Countries of Origin

Myanmar; Cameroon; Papua New Guinea; Angola; Paraguay; Portugal; Oman; Armenia; Greece; Austria; Mongolia; Mozambique; El Salvador; Morocco; Unknown; Brazil; Algeria; Cabo Verde; Chile; Lesotho; Argentina; Iran (Islamic Republic of); Hungary; Republic of Kosovo; Japan; Ukraine; Taiwan (Province of China); Bolivia (Plurinational State of); India; New Zealand; Canada; Vanuatu; Turkey; United States Minor Outlying Islands; Namibia; Comoros; Finland; Honduras; Italy; South Africa; Antarctica; Peru; Ethiopia; Germany; Yemen; Tanzania, United Republic Of; Afghanistan; Eritrea; Russian Federation; Viet Nam; Czechia; Guinea; United States of America; Egypt; Chad; Madagascar; Thailand; United Kingdom of Great Britain and Northern Ireland; Equatorial Guinea; Kiribati; Libya; Saudi Arabia; Sweden; Malawi; China; Poland; Slovakia; Bulgaria; France; Jordan; Serbia; Romania; Syrian Arab Republic; Niger; Sri Lanka; Uzbekistan; Kenya; Switzerland; Spain; Djibouti; Azerbaijan; Nicaragua; Congo (the Democratic Republic of the); Denmark; Mexico; Uganda; Australia; Estonia; Indonesia

Care

Sanidine is brittle so gentle handling is recommended. Avoid ultrasonic cleaners.

Instagram
Facebook
YouTube

Sign up for the latest from Gemstones.com!

 
 
  • About Us
  • Terms & Conditions
  • Privacy Policy
  • Sitemap
  • Contact Us
  • Request a Partner Invitation
  • Your Privacy Choices CCPA Icon

©  America's Collectibles Network, Inc. All Rights Reserved.