Almandine

a mineral, red iron aluminum garnet.
Historical Examples

The almandine produces characteristic bands in the green and the jargoon in the red, green and blue portion of the spectrum.
Scientific American Supplement, No. 1082, September 26, 1896 Various

It seems related to both almandine and pyrope, and shows the absorption-spectrum of almandine.
Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 4 Various

almandine, al′man-dīn, n. a red transparent variety of the garnet.
Chambers’s Twentieth Century Dictionary (part 1 of 4: A-D) Various

One is the variety of red garnet known as almandine, and the other is the jargoon.
Scientific American Supplement, No. 1082, September 26, 1896 Various

Almandite garnet, the “almandine” of the jeweler is less abundant than pyrope, when of gem quality.
A Text-Book of Precious Stones for Jewelers and the Gem-Loving Public Frank Bertram Wade

In this way we are enabled to identify a jargoon or an almandine merely by looking at it.
Scientific American Supplement, No. 1082, September 26, 1896 Various

All the almandine garnets which I have examined, and nearly all the jargoons, show these characteristic absorption spectra.
Scientific American Supplement, No. 1082, September 26, 1896 Various

almandine garnets also show no dichroism and lack variety of color.
A Text-Book of Precious Stones for Jewelers and the Gem-Loving Public Frank Bertram Wade

After quartz come corundum (Oriental amethyst), spinel (almandine spinel), garnet (almandine), and spodumene (variety kunzite).
A Text-Book of Precious Stones for Jewelers and the Gem-Loving Public Frank Bertram Wade

noun
a deep violet-red garnet that consists of iron aluminium silicate and is used as a gemstone. Formula: Fe3Al2(SiO4)3