Although originally named for the first location it was found, Bastnas Mine, Riddarhyttan, Vastmanland, Sweden, subsequent deposits have been located in Norway, Malawi, Mongolia, Canada and California.
- Empirical Formula: Ce(CO3)F
- Color is pale white, tan, gray, brown, yellow and pink.
- Luster is pearly, vitreous, greasy to dull.
- Transparency: Crystals are translucent to opaque.
- Crystal System is hexagonal.
- Cleavage is distinct in one direction (basal) and poor in three directions (prismatic).
- Fracture is uneven.
- Hardness is 4 to 4.5.
- Specific Gravity is 4.7 to 5.0 (well above average)