Blue Calcite with Hematite Inclusions
Calcite var. Blue · Mineral Specimen / Semi-Precious Gemstone
Crystal System
Trigonal crystal system; typically occurs in massive, rhombohedral, or granular habits.
Mineral Group
Carbonates; Calcite group
Chemical Formula
CaCO3 (Calcium Carbonate) with Fe2O3 (Hematite) trace inclusions
Formation Process
Sedimentary or Metamorphic; typically forms through chemical precipitation in marine environments or hydrothermal veins.
About This Crystal
The specimen shows a distinct bicolored appearance with a sky-blue upper section and an earthy reddish-brown lower section. It possesses a vitreous to waxy luster, is translucent to opaque, and displays characteristic rhombohedral cleavage planes on the surface.
Physical Characteristics
Color: Blue and reddish-brown; Streak: White; Cleavage: Perfect rhombohedral in three directions; Fracture: Conchoidal to uneven; Specific Gravity: 2.71; Fluorescence: May show weak red or pink under LWUV.
Optical Properties
Refractive Index: 1.486 - 1.658; Birefringence: Extremely high (0.172); Optical Character: Uniaxial negative; Pleochroism: Weak.
Hardness & Durability
Origin Region
Madagascar and Mexico are the primary sources for this blue and reddish-brown color combination found in massive form.
Hardness & Durability
Mohs Hardness: 3; very soft and brittle. Not suitable for rings; high sensitivity to scratching and impact due to perfect cleavage.
Care & Maintenance
Avoid all acids (including vinegar) as they will dissolve the stone. Clean only with warm soapy water. Store away from harder stones to prevent scratching.
Rarity & Value
Common; relatively inexpensive mineral. Value is based on the distinctness of the color zoning and the size of the specimen.
Special Characteristics
The reddish-brown coloration is caused by iron oxide (Hematite) staining or inclusions within the calcite lattice. Shows strong double refraction in transparent pieces.
Lore & History
Historically used in various cultures for lime production and carvings. In metaphysical traditions, blue calcite is associated with the throat chakra and communication, while the red/brown inclusions are thought to provide grounding energy.