Larvikite
Larvikite is a feldspar-rich igneous rock famous for blue-silver flashes from feldspar crystals. It is often sold as decorative stone and can be confused with labradorite-bearing rocks.
Larvikite properties at a glance
| Type | Igneous Rocks |
|---|---|
| Chemical formula | Feldspar-rich monzonitic intrusive rock |
| Mohs hardness | 6 |
| Luster | vitreous |
| Streak | White to light gray |
| Cleavage | Variable by feldspar grains |
| Fracture | Uneven to granular |
| Specific gravity | 2.75 |
| Transparency | opaque |
| Common colors | Dark gray, Blue gray, Black, Silver blue, White |
| Rarity | common |
Geology & background
Forms when feldspar-rich magma cools slowly underground, producing coarse crystals that can show blue-silver feldspar iridescence.
Larvikite is a well-known Norwegian decorative stone and a useful example of feldspar-rich intrusive igneous rock.
How to identify Larvikite
- Look for dark gray to black feldspar-rich rock with blue-silver flashes.
- Larvikite is usually coarse grained and igneous, not a single mineral crystal.
- Polished surfaces show the feldspar flash much better than rough weathered surfaces.
- Do not confuse it with Labradorite; larvikite is a rock, while labradorite is a feldspar mineral.
Where Larvikite is found
Classic larvikite comes from the Larvik region of Norway, with related feldspar-rich rocks reported elsewhere.
How much is Larvikite worth?
| Entry-level specimen | $5 |
|---|---|
| Typical collector specimen | $40 |
| Premium specimen | $300+ |
Larvikite is usually valued for teaching, field context, locality, texture, color, mineral content, or unusually attractive specimens rather than high gem value.
Common uses
- Decorative stone
- Countertops and tiles
- Collector specimens
- Field identification
Interesting facts
- Larvikite is named after the Larvik area of Norway.
- Its blue-silver sheen comes from feldspar crystals, not from a separate blue mineral coating.
- It is widely used as polished architectural and decorative stone.
Care & safety
Larvikite can vary in toughness, porosity, vesicles, glass content, and weathering depending on cooling history and mineral mix.
Avoid inhaling dust. Do not cut, grind, or polish unknown igneous rocks without eye protection and a properly rated respirator.
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