Rockland Kenya Limited · Tsavo West, Kenya Tsavo West, Kenya
The John Saul Ruby Mine.
Rockland Kenya Limited was founded in 1991 and acquired the John Saul deposit that same year. The mine lies inside Tsavo West National Park in Taita Taveta County.
01 Discovery
The 1973 discovery.
American prospectors John Saul and Tim Miller discovered the ruby deposit in 1973. It became known as the John Saul Ruby Mine and sits within the East African Gemstone Belt in south-eastern Kenya.
The mine later passed through a long period of inactivity and dispute. Rockland Kenya Limited acquired it in 1991 and has operated it since.
- Discovered
- 1973
- Discovered by
- John Saul and Tim Miller
- Acquired by Rockland
- 1991
- Location
- Tsavo West National Park, Taita Taveta County
02 The lease
Special Mining Lease No. 19.
Rockland received Special Mining Lease No. 19 in 1991. The lease covers a defined area inside Tsavo West National Park. Its original twenty-one-year term was renewed in 2012.
The route to the mine passes through the Kenya Wildlife Service gate at Kasigau and continues into dry, thorn-covered bush.
- Lease
- Special Mining Lease No. 19
- Granted
- 1991, for a term of 21 years
- Renewed
- 2012
- Access
- Kasigau gate, Kenya Wildlife Service
03 The ground
Geology of the deposit.
The mine is part of the Mozambique Metamorphic Belt, a geological structure that runs from Mozambique through Tanzania to the Kenyan coast. The belt dates to roughly five hundred million years ago.
At John Saul, the ruby occurs around a heavily altered ultramafic body within gneiss and schist. Pegmatites and desilicified fracture zones form the main mineralised areas.
Chromium in the host rock gives the ruby its red and pink colour. The deposit is low in iron, and its stones are known for strong colour and fluorescence.
- Belt
- Mozambique Metamorphic Belt
- Host rock
- Gneiss and schist with an altered ultramafic body
- Mineralisation
- Pegmatites and desilicified fracture zones
- Colour
- High chromium, low iron
04 The method
From open cast to underground.
Open cast mining removes the overburden with heavy machinery and works down through a series of benches cut into the pit. This was the mine's original working method.
A geological review in 2000 recommended taking the Kimbo vein underground. Rockland introduced underground mining in 2008, using vertical shafts and horizontal adits. A crane hoists the mined material to the surface.
- Open cast
- Benches cut in vertical levels, overburden removed
- Underground since
- 2008
- Underground method
- Vertical shafts and horizontal adits
- Hoisting
- By crane through the shafts
05 Rock to parcel
From rock to parcel.
Material is weighed as it moves through the mine. After the ruby has been separated by hand, the selected stone and the remaining rock are accounted for before processing continues.
-
01
Weighing
All material is weighed, and its weight is accounted for at every stage that follows.
-
02
Sorting and washing
Ruby is separated from the rock by hand, then washed and cleaned.
-
03
Grading
Stones are graded into three levels on the factors used to establish value.
-
04
Sizing
Stones are grouped by size, because buyers often want parcels of matching size.
-
05
Sealing and dispatch
Parcels are sealed and taken to the Nairobi head office under night escort.
06 The company
Rockland Kenya Limited.
Rockland Kenya Limited was founded in 1991 under Hon. Johnson Muthama, the company's executive chairman. The business was established around the acquisition and operation of the John Saul Ruby Mine.
Hon. Muthama is a founding member and former chairman of the Kenya Chamber of Mines. Rockland's head office is in Gigiri, Nairobi.
- Founded
- 1991
- Founder and executive chairman
- Hon. Johnson Muthama
- Kenya Chamber of Mines
- Founding member; former chairman
- Head office
- 58 Redhill Road, Gigiri, Nairobi
Security, medical facilities, staff transport and the sorting floor.