Xenotime

Xenotime (from the Greek words xenos, "foreign", and time, "honour") is a Rare Earth phosphate mineral, whose major component is yttrium orthophosphate (YPO4). It forms a solid solution series with chernovite-(Y) (YAsO4) and therefore may contain trace impurities of arsenic, as well as silicon dioxide and calcium. The Rare Earths dysprosium, erbium, terbium, and ytterbium, and metal elements like thorium and uranium (all replacing yttrium) are the expressive secondary components of xenotime. Due to uranium and thorium impurities, some xenotime specimens may be weakly to strongly radioactive. Lithiophyllite, monazite, and purpurite are sometimes grouped with xenotime in the informal "anhydrous phosphates" group. Xenotime is used chiefly as a source of yttrium and heavy lanthanide metals (dysprosium, ytterbium, erbium, and gadolinium). Occasionally, gemstones are also cut from the finer xenotime crystals.
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Noun
1. a brown-to-yellow mineral that is a phosphate of yttrium in crystalline form
(hypernym) mineral
(substance-meronym) thulium, Tm, atomic number 69

(n.)
A native phosphate of yttrium occurring in yellowish-brown tetragonal crystals.
  

General Information:
 Chemical Formula:
YPO4
 Composition:
(Molecular Weight = 183.88 gm)
Yttrium 48.35 % Y 
Phosphorus 16.84 % P 
Oxygen 34.80 % O 
 Empirical Formula:
Y(PO4)
 IMA Status:
Approved IMA 1987
 Name Origin:
From the Greek xenos - "foreign" and time - "honor."
Physical Properties:
 Cleavage:
[100] Perfect
 Color:
yellowish brown, greenish brown, gray, reddish brown, or brown.
 Density:
4.4 - 5.1, Average = 4.75
 Diaphaniety:
Opaque
 Habits:
Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite), Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline)., Massive - Granular - Commo n texture observed in granite and other
 Hardness:
4-5 - Fluorite-Apatite
 Luminescence:
None.
 Luster:
Vitreous - Greasy
 Streak:
white
More details...

General Information:
 Chemical Formula:
YbPO4
 Composition:
(Molecular Weight = 268.01 gm)
Ytterbium 64.56 % Yb
Phosphorus 11.56 % P 
Oxygen 23.88 % O 
 Empirical Formula:
Yb(PO4)
 Environment:
Found in the saccharoidal albite unit of a granitic pegmatite. Forms a series with xenotime-(Y).
 IMA Status:
Approved IMA (Dana # Added)
 Locality:
Shatford Lake pegmatite group, near the margin of the Lac du Bonnet batholith, southeastern Manitoba.
 Name Origin:
Named after its composition and relationship with xenotime-(Y).
Physical Properties:
 Cleavage:
None
 Color:
colorless, yellowish white, or brownish white.
 Diaphaniety:
Transparent
 Habits:
Inclusions - Generally found as inclusions in other minerals., ,
 Hardness:
-
 Luminescence:
Non-fluorescent.
 Luster:
Vitreous (Glassy)
 Streak:
white
More details...

XENOTIME. XENOTIMO