“Nigrozero” is the only one running deposit of garnet amphibolites and one of the most developed deposits of highly-ornamental hard rocks in North region of Russia. The deposit is situated on a hill slope right on the Arctic Circle. The total square of the quarry is 4,87 hectares. The explored reserves of stone are 1 404,8 thous. m3.
The extraction is being carried out with diamond wire-sawing technology. It gives an opportunity to obtain blocks of higher quality and bigger sizes, with right-angled shape and to decrease the expenses.
The extraction is seasonal from April for November.
“Nigrozero” garnet amphibolite
“Nigrozero” garnet amphibolite (“Tundra”, in Europe also known as “Nordic Sunset”) is a high-ornamental hard rock. Due to polychrome tint with predominance of black, fine-grained structure, striped-and spotted texture of “Tundra” (“Nordic Sunset”) you can create refined interiors with inimitable in its beauty wall panels of big sizes. The picture variations of the stone depend on the direction of sawing. You can implement “Tundra” for wall-cladding, tomb-stones and for city amenities. It is equally fine with all types of face furnishing. Polished surface displays an inimitable texture of material.
- Type of natural stone: garnet amphibolite
- Commercial name: “Tundra” (in Europe also known as “Nordic Sunset”).
- Geological age: Ar1 3 000 - 3 200 Ma
- Annual extraction of blocks: up to 3 000m3 (extraction is seasonal)
- Deposit: “Nigrozero”
- Location: Russia, Republic of Karelia, Loukhi district, Chupa village, 50 km from Chupa railway station, 1000 km from St. Petersburg sea port, 1200 km from Kotka sea port (Finland).
- Within the area of “Nigrosero” deposit the subtype of the material is enabled. The material is more white then “Tundra” and calls“Ice Tundra”
| Index description | Unit of measuring | Value |
|---|---|---|
| Density | kg/m3 | 2953 |
| Water absorption | % | 0,225 |
| Compressive strength in dry condition | MPa | 136,55 |
| Compressive strength in wet condition | MPa | 112,75 |
| Freese resistance | F | F 100 |
| Salt resistance | % | 0,125 |
| Wear resistance | g/cm2 | 0,41 |
| Stroke resistance | cm | 72,5 |
| Index description | Unit of measuring | Value |
|---|---|---|
| Plagioclase | % | 15 |
| Garnet | % | 8 |
| Amphibole | % | 52 |
| Quartz | % | 10 |
| Biotite | % | 0,25 |
| Secondary minerals (zoisite, sericite) | % | 9,25 |
| Ore inclusions | single grains | |
| Accessory minerals | % | 2 |
| Index description | Unit of measuring | Range of indexes | Average indexes |
|---|---|---|---|
| Specific effective activity in ERN | Bk/kg | 36-44 | 40 |
| Application according to radiation factor | Building raw material of I class NBR-99 |
| Structure | Inequigranular structure (from fine to coarse) |
| Texture | Massive, stripped, knotty, puckered |
| Color | Mixed picture and color with alteration of dark homogeneous areas mainly of biotite and amphibole composition and knotty-stripped areas of light-grey and white quarts and plagioclase and areas with uneven allocated garnet grains. |
| Ornamental index | II, I class (Аd = 27-34,8 points) – ornamental, high-ornamental |
| Polishing index | 140-170 (Оp) – I class |
| Technological index | Not spesified |
Types of Face finishing
Polished
Aqua-jet
Bush-hammered
Rock-faced
Flamed
Grind
garnet amphibolite “Ice Tundra”
