Our team

Our global team consists of the most experienced engineers & specialists in the mining industry - pioneers who spent nearly two decades learning from our mistakes. 


Executive Management

"There's no time like now to do things"

Geoffrey Madderson

Chief executive officer


Over 15 years international experience in the Mining Industry. Has held positions in South Africa, Germany & London in Business Development, Sales and Executive Management of STARK. 

"We may build plants, but the true goal is to build people"

Jaco Prinsloo

Chief operation officer B.Ing Mech Eng / PMP


Twenty one years working experience including detailed mechanical machine design and construction, business development and implementation experience, Petro-chemical, and mineral processing. 

"Let’s go agile plant development!"

Fabian Riedel

Chief Technical Officer Dipl.-Ing. Mining Engineering 


Twenty years of experience in sensor-based sorting applications in mineral processing and mining. Positions held as VP Sales, Technical Director, Country Manager and General Mine Manager in South Africa and Germany. 

"In consistency lies the victory."

Nico van Niekerk

Managing director South Africa MBA / B.Eng Elc Eng 


Presenting 30 years’ experience in leading Industry Technology and Enterprise Technology Infrastructure projects. 

"Research the problem, make a plan and execute it."

Dian Heinrich Page

Managing director Germany Pr.Sci.Nat / M.Eng Geo Tech


Ten years of exploration and mining experience, with broad exposure to modern exploration and mining procedures in areas of mineral resource management of projects. 

"Stay curious."

Gunnar Kläschen

Head of Value Proposition Dipl.-Kfm.


Eighteen years experience of marketing and sales in different B2B business areas for mostly international companies.  

"I love smart tools."

Sonja Hoyng

MD & Head of Marketing Operations B.A. International Management


Twenty years+ in automotive marketing, servicing in agencies and consultancy consolidated in one person.  


"Step by step with total commitment."

Lode Theunynck

head of customer experience-


High performing sales leader with 20+ years of experience in managing multi-million growth and development on a global scale of Container Terminal, Metallurgy and Mining markets.

Annelize Fouche at Stark

"Make the plant of the future happen today."

Annelize Fouchee



Ten years of mineral processing and equipment design experience, with comprehensive understanding of integration and optimisation of mineral beneficiation and bulk materials handling equipment.

"A project is late one day at a time- Act Now!"

Rynard Brits

Mineral Resource Manager Pr.Sci.Nat / MSc Engineering Management


Ten years’ experience in hard rock OC mining and quarrying, underground stope mapping, conducting geological field studies, desktop studies and exploration. 

Eleanore Forner at Stark Resources

"Seek out new technologies. Decarbonize where you can. Always Optimize."

Eleanore Luise Forner

Head of Energy Pr.Chem.Eng / B.Eng Hons


Fourteen years experience as a process/project engineer, with a multi-industry career, starting in nuclear (Uranium and fluorochemicals), to mining and hydrometallurgy across various metals.

Jolene Saaiman Stark

"In a world that’s changing really quickly, the only strategy that is guaranteed to fail Is not taking risks."

Jolene Saaiman

Economic Metallurgist MBA, BEng, Metallurgical Engineering


Ten years of key account management and business development experience with key OEMs in the Power Transmission, Heavy Industry and Off-highway markets in South Africa.

"Your mountain is waiting, so get on your way" - Dr. Seuss

James Henry Ferreira

Process Manager MSc App Sc: Metallurgy / BSc Hons App Sc: Metallurgy / BSc Geology


Five years’ working experience in hard rock mining, quarrying and minerals processing industry, entailing mining and plant operations. 

“Problems are for people who don’t seek solutions.”

Eugene Collins

Fine Minerals Specialist B.Eng Chem Eng


4 years of experience in the mining and mineral processing environment with specific regard to beneficiation unit operations. 

“Always on the leading edge of new technologies and new combinations of new technologies.”

David Madderson

Head of Sensor-Based Sorting South America


Led the introduction of sensor-based sorting into the mainstream mining industry in 1999/2000. Inventor and patent holder of several processes. Focus on fine and ultra-fine mineral recovery. 

"Consider the variables, prioritize the options, then Just Do It."

George Henry Read

Senior Technical Advisor Canada P.Geo


Over 38 years as an international diamond exploration and evaluation geologist working in Southern Africa, Mali, Canada, United States, Brazil, Australia and Greenland. I am familiar with diamond bulk sample plants. 

"Every challenge presents an opportunity to think creatively and critically."

Dr Zac Phillips

Head of Energy Finance PhD Pr.Chem.Eng


In excess of twenty-seven years’ experience in energy and finance, working for companies such as BP, Chevron, Merrill Lynch and ING Barings, where he undertook finance or finance related roles. 


“The capacity to learn is a gift; The ability to learn is a skill; The willingness to learn is a choice.” - Brian Herbert

Jean-Pierre Smith

Director Stark Technologies B.Eng Mech Eng


Mechanical Engineer with vast experience in the mining and diamond sorting sector. Technical expertise is predominantly in the form of Project Management and Project Planning.

"If it was easy everyone would do it."

Hennie Du Plessis

Head of Product Development


32 years local and international experience in Radio Frequency (RF) Electronics in a wide variety of products.

"Always learning, always growing and always setting higher goals to achieve."

Emmanuel Francis

Product Support Engineer Bsc (Hons) Mechatronics Engineering


Mechatronics Engineer passionate about robotics, artificial intelligence, machine learning, embedded systems and energy conversion and sustainability.

"Think outside the box for new solutions."

Lourens De Villiers

Principal Mechanical Engineer B.Eng Mech Eng


Fifteen years of experience in engineering design, analysis, product development and fabrication.

“Make it simple, but significant.”

Reinald Liebenberg

Mechanical Design Engineer B.Eng Mech Eng


Three years of experience in mechanical design and development of prototype products with exposure to multiple fields.

"Technology is best when it brings people together."

Ryan Opperman

Mechanical Design Engineer B.Eng Mech Eng


Qualified Mechanical Design Engineer with experience in the mining and diamond sorting sector.


"The best way to begin is just to start."

Willem Viljoen

Senior Project Engineer B.Tech Mech Eng


Nine years of mineral processing experience, with extensive experience in bulk material handling processes and sensor based sorting.  

Mauritz Van Der Heever at Stark Resources

"Never accept failure, but learn from your mistakes."

Mauritz Van Der Heever

Project Coordinator


Ten years of experience in mining and metal industry with an extensive background in construction and project management in Africa. 

“If opportunity doesn’t knock, build a door.” – Milton Berle

Franko Terblanche

Mechanical Project Engineer


6 years of experience as a mechanical project engineer across 3 sectors. Namely Steel, modular process plants and Modular diamond sorting plants.

“A goal without a plan is just a wish"

Eduan De Langen

Electrical Engineer


Six years of electrical engineering experience in a heavy industrial environment, with comprehensive exposure to the mining and mineral processing.  

“By failing to plan you are only planning to fail.”

Wesley Dean Slabbert

Project Planner


Coming from modest beginnings as a fitter & turner apprentice with Otmar Machine Tools and growing within the engineering industry. 

"I love integrating environmental thinking into process engineering."

Elanie Meyer

Lead Process Engineer B.Eng Chem Eng.


Eleven years working experience in the mining industry, specific to diamond and ruby mining. My key role over my career is focused on processing design and execution.

"Our future success is directly proportional to our ability to understand, adopt and integrate new technology into our work."

Raymond Fourie

Process Engineer B.Eng Chem Eng


Four years working experience in the mining and minerals processing industry, entailing research and development management and design execution.

“Do the best you can until you know better. Then when you know better, do better.” -Maya Angelou

Claudia Rose Hannweg

Junior Mechanical Engineer B.Eng


Completed Grade 12 in 2015 at St Mary’s DSG in Pretoria. Highlights of schooling include being awarded a scholarship in high school.

Finance & Administration


Sonja Zeelie

Finance Manager



"If you can imagine it, you can achieve it. If you can dream it, you can become it." -William Arthur Ward

Marius Engelbrecht

Operations Manager


More than 15 years’ experience in Finance and Human Resource Management, specializing in Tax and is an active member with the South African Institute of Taxation.

"If someone offers you an amazing opportunity and you’re not sure you can do it, say yes – then learn how to do it later."

Amanda Prinsloo

Senior Administration Manager


20 Years of HR/Payroll experience, administrative experience in employing Cross Border (DRC, Burkina Faso, Ghana, Guinea) as well as in South Africa. 

“The way to achieve your own success is to be willing to help somebody else get it first.”

Ilse Scholtz

Cost Controller


A person with great experience and a great attitude. 

“We can’t help everyone, but everyone can help someone” – Ronald Reagan

Vanessa Mostert

HR Manager BCom Hons IOP


Human Resources professional with over 8 years’ experience consulting in various industries. Passionate about people and processes.

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Locations worldwide

United Kingdom

Stark Ltd
Sovereign House,
Port Causeway
United Kingdom, CH62 4TP


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