Larvikite
What is Larvikite?
Larvikite is a variety of monzonite, notable for the presence of thumbnail-sized crystals of feldspar. It’s primarily found in the Larvik area of Norway, hence its name. Larvikite is often used as a decorative building material as well as a gemstone.
Larvikite is a unique gemstone that comes in shades of grey with blue or silver flashes. Its unique appearance and color make it a popular choice for countertops and decorative items, as well as jewelry like pendants and beads.
| Chemical Classification | Inorganic - Silicate |
| Color | Predominantly grey with blue or silver reflections. |
| Streak | White |
| Luster | Vitreous to pearly. |
| Transparency | Opaque. |
| Occurrence | Primarily found in the Larvik Fjord region of Norway. |
| Formation | Formed during the cooling of magma chambers. |
| Diaphaneity | Opaque |
| Cleavage | None |
| Mohs Hardness | 6 - 6.5. |
| Specific Gravity | Approximately 2.55 - 2.75. |
| Diagnostic Properties | Blue to silver labradorescence. |
| Chemical Composition | Anorthoclase (Na,K)AlSi3O8 and Augite (Ca,Na)(Mg,Fe,Al)(Si,Al)2O6 |
| Pleochroism | Not observable due to its opacity. |
| Crystal System | Monoclinic |
| Optical Properties | Biaxial (+) |
| Refractive Index | Varies due to mixture of minerals |
| Birefringence | Varies due to mixture of minerals |
| 2V angle | Measured: 58° |
| Dispersion | Not typically noted due to its opacity. |