16.8.5: Spessartite

Last updated
Save as PDF

Page ID: 4136

gemology
Gemology Project

\( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)

Spessartite Garnet
Chemical composition	Mn₃Al₂(SiO₄)₃anganese aluminum silicate
Crystal system	Cubic
Habit	Dodecahedra
Cleavage	None
Hardness	7
Optic nature	Isotropic
Refractive index	1.795-1.815
Birefringence	None
Specific gravity	4.12-4.20
Lustre	Vitreous

Figure \(\PageIndex{1}\): Spessartite with Smoky Quartz
Photo courtesy of Barbra Voltaire

Spessartite image gallery

Spessartite is also named spessartine, both names are used interchangeably.

Diagnostics

Color

Orange, red, reddish-orange to yellowish-brown.

Spectroscope

Spessartite shows a typical spectrum due to manganese (idiochromatic) and some iron (from almandine).

Figure \(\PageIndex{2}\): Spectra of a spessartite from the Loliondo deposit in tanzania which was discovered in 2007. The graphs represent the transmission spectrum taken with the aid of a spectrometer, the spectrum below is what you will see through a spectroscope

Inclusions

Feathers of liquid droplets ("shredded inclusions"), negative crystals, crystal inclusions, "suger"; multiple tiny grains (Tanzanian stones) , small colorless fibers of tirodite which cause a sleepy look (Namibian stones)

Specific gravity

4.12 - 4.20

Spessartite sinks in all common heavy liquids.

Chelsea Colour Filter

Spessartite will show red under the CCF.

Varieties

Mandarine/Kashmirine/Hollandine

Three names for the same intense orange variety of spessartite.

Malaia

Main entry: pyrope

Malaia garnet (or malaya garnet) is the red-orange variety of pyrope-spessartite.

Localities

Sri Lanka (Ceylon)	Burma	Brazil
Madagascar	Mozambique	Nigeria
Namibia	Tanzania	USA
China	Pakistan	Afghanistan
Myanmar	India	Italy
Norway	France	Germany
Sweden	Scotland	Russia