THE MINERAL XENOTIME

[SunKat]

Xenotime is one of the very few minerals, let alone words, that starts with the letter X; a good word to remember in some word games. It is a widely spread mineral throughout the world although good crystals and therefore specimens are somewhat hard to find.

It is one of the few yttrium minerals known to science. Wakefieldite and chernovite-(Y) are other yttrium minerals, although a vanadate and an arsenate respectively. Often uranium or other rare elements such as erbium, thorium, ytterbium, zirconium and the not so rare calcium are found as traces in xenotime replacing the yttrium. Due to the presence of at least some of these radioactive elements, xenotime is frequently slightly radioactive.

PHYSICAL CHARACTERISTICS:

* Color is most commonly various shades of brown but also gray, greenish brown, muted red and yellow.
* Luster is vitreous to resinous.
* Transparency: Crystals are translucent to opaque.
* Crystal System is tetragonal; 4/m 2/m 2/m
* Crystal Habits include stubby to elongated prismatic crystals that are terminated by variously slanted dipyramids. Also known for nice rosette and radial aggregates.
* Cleavage is perfect in two prismatic directions.
* Fracture is uneven.
* Hardness is 4 - 5
* Specific Gravity is approximately 4.4 - 5.1 (heavy for translucent minerals)
* Streak is pale brown to yellow or red.
* Other Characteristics: Trace amounts of uranium and other rare earth elements may render crystals slightly radioactive.
* Associated Minerals are quartz, micas especially biotite, monazite and some feldspars.
* Notable Occurrences include Arendal, Hittero and Tvedestrand, Norway; Madagascar; several locations in Brazil and also in the United States in Colorado, California, Georgia and North Carolina.
* Best Field Indicators are color, crystal habit, cleavage, softness and luster.

[SunKat]

Your welcome Linda. I had to go and look for it and I found this today:

Xaga
Xaga is a type of obsidian found in California, USA.

Xalostocite
Xalostocite is a pink grossular garnet that is found in a matrix of white marble. Xalostocite is found in Xalostoc, Mexico.

Xyloid Jasper
Xyloid jasper is jasperized wood (petrified wood). It is wood that has fossilized - all the original chemicals have been replaced with minerals, making a stone-like replica of the original wood.