Recently Released Special Editions
Systematic Micaceous Minerals
Not all micaceous looking minerals fall in the MICA group of phyllosilicate minerals. Many of the other silicates appear micaceous but are not. We'll have a look at some of these minerals and hopefully explain the difference. Take a look at our article on Mica and Other Micaceous Minerals.
Phlogopite
- Sold
- Add to Favorites
- Locality
- Balmat, St. Lawrence Co., New York, United States
- Formula
- KMg3(Si3Al)O10(OH)2
- Availability
- Sold
- Size
- 6 x 4 x 2 cm - Sm Cabinet
Phyllosilicate - Monoclinic - Mica group member. End member. Ordinary (True or Common) Mica - Trioctahderal with Mg at the (M) positions, K as (I), and OH as (A). Mg end member of Biotite-Phlogopite series.
Occurs sometimes as primary mineral in igneous rocks, mainly ultrabasic, in Leucite-pyroxene rock called "Wyomingite", serpentenized dunnites, altered kimberlites, alkaline ultrabasic rocks in Kola, Russia.
Scaly mass.
Phlogopite
- Formula
- KMg3(Si3Al)O10(OH)2
- Crystal System
- Monoclinic
- Crystal Habit
- Micaceous, Scaly, Lamellar
- Cleavage
- Perfect, None, None
- Luster
- Vitreous - Pearly
- Color
- brown, gray, green, yellow, reddish brown
- Streak
- white
- Class
- Monoclinic - Prismatic
- Fracture
- Uneven
- Hardness
- 2-2.5
- Collection
- Phillips Collection
- Mineralpedia
- View Phlogopite
- On Dakota Matrix
- Previously Sold Phlogopite
- On Dakota Matrix
- Other Available Phlogopite
- WebMineral
- View Phlogopite
- Mindat
- View Phlogopite
Polylithionite
- Sold
- Add to Favorites
- Locality
- Lepkhe-Nel'm Mt, Seidozero Lake, Lovozero Massif, Kola Peninsula, Russia
- Formula
- KLi2AlSi4O10F2
- Availability
- Sold
- Size
- 3 x 2.5 x 2.5 cm - Thumbnail
Phyllosilicate - Monoclinic - Mica group member. End member. Ordinary (True or Common) Mica - Trioctahderal with lithium and aluminum in the (M) positions, Si and boron in the (T) positions, F>OH in the (A) position and K as the Interlayer cation.
Occurs as tabular crystals with hexagonal outline, also scaly, fine grained, white, gray, pale green, pale pink and violet. Can be fluorescent green. Typically found in alkaline syenites and their pegmatites including MSH and Ilimaussaq.
A nice specimen with colorless plates of Tainiolite.
Polylithionite
- Formula
- KLi2AlSi4O10F2
- Crystal System
- Monoclinic
- Crystal Habit
- Pseudo Hexagonal, Tabular, Scaly
- Cleavage
- Perfect, None, None
- Luster
- Pearly
- Color
- bluish, colorless, violet, greenish, pearl white
- Streak
- white
- Class
- Monoclinic - Prismatic
- Fracture
- Uneven
- Hardness
- 2-3
- Collection
- Phillips Collection
- Mineralpedia
- View Polylithionite
- On Dakota Matrix
- Previously Sold Polylithionite
- On Dakota Matrix
- Other Available Polylithionite
- WebMineral
- View Polylithionite
- Mindat
- View Polylithionite
Polylithionite
- Sold
- Add to Favorites
- Locality
- Ilimaussaq complex, Narsaq, Kitaa prov., Greenland
- Formula
- K(Li, Al)2[(F, OH)2|(Si, B)4O12
- Availability
- Sold
- Size
- 8 x 5.5 x 2.5 cm - Sm Cabinet
Phyllosilicate - Monoclinic - Mica group member. End member. Ordinary (True or Common) Mica - Trioctahderal with lithium and aluminum in the (M) positions, Si and boron in the (T) positions, F>OH in the (A) position and K as the Interlayer cation.
Occurs as tabular crystals with hexagonal outline, also scaly, fine grained, white, gray, pale green, pale pink and violet. Can be fluorescent green. Typically found in alkaline syenites and their pegmatites including MSH and Ilimaussaq.
This is a larger specimen with Aegerine and a Copenhagen label.
Polylithionite
- Formula
- KLi2AlSi4O10F2
- Crystal System
- Monoclinic
- Crystal Habit
- Pseudo Hexagonal, Tabular, Scaly
- Cleavage
- Perfect, None, None
- Luster
- Pearly
- Color
- bluish, colorless, violet, greenish, pearl white
- Streak
- white
- Class
- Monoclinic - Prismatic
- Fracture
- Uneven
- Hardness
- 2-3
- Collection
- Phillips Collection
- Mineralpedia
- View Polylithionite
- On Dakota Matrix
- Previously Sold Polylithionite
- On Dakota Matrix
- Other Available Polylithionite
- WebMineral
- View Polylithionite
- Mindat
- View Polylithionite
