Cerite (Ce) Ferriallanite (Ce) 2.06 ct

Cerite is a complex silicate mineral group that contains cerium, lanthanum, and calcium, among other elements. Its chemical formula is typically represented as

(Ce,La,Ca)9​(Mg,Fe3+)(SiO4​)6​(SiO3​OH)(OH)3​

¹². Here are some key characteristics:

• Color: Clove-brown with a reddish tinge; can also appear pale lavender-brown to colorless in thin fragments.
• Crystal System: Trigonal.
• Hardness: 5 to 5.5 on the Mohs scale.
• Luster: Vitreous to resinous.
• Streak: White to greyish white.
• Specific Gravity: 4.7 to 4.86¹.

Cerite was first described in 1803 from an occurrence in Bastnäs, Västmanland, Sweden¹. There are two main species: cerite-(Ce), which is rich in cerium, and cerite-(La), which is rich in lanthanum².