Platinum is Zimbabwe's long-term mineral earner, diamond markets are very fickle, most gold has been dug out over the last 500 years and Zimbabwe is too far from the sea to be a major player in world base metal markets.
So it is critical that our platinum reserves, the second largest in the world and the cheapest large deposits to mine, are exploited sensibly and carefully to give full value to the country. Demand should grow steadily, since platinum is an industrial metal required as a catalyst in many processes, and especially in cleaning exhaust fumes from motor vehicles.
Chinese and Indian cities are going to need properly equipped cars if their populations are going to continue to breathe, so we can look forward to ever larger sales.
So far Zimbabwe has done fairly well. Large South African concerns have invested heavily; the first stage of indigenisation, the trusts for local communities who actually had the ore under their lands and so were morally entitled to a "fee", has gone well. But now Zimbabwe needs to figure out how to expand production steadily and gain maximum value from this mining.
Zimplats, the largest producer, is seeing its exclusive prospecting area cut by 28 000 hectares. This is normal. Until ore bodies are properly mapped, an investor needs the security of a large area for investigation.
Even when you know there is platinum, or any other mineral, in an area you still need to know how much there is and precisely where it is before you can move into the mining stages and even then you need to know where there will be enough ore to keep the mine in operation for its full lifetime.
But once the position and grade of ores are better known, then a far smaller area can be exploited for decades before new ore bodies are needed by that mine.
So long as Zimplats has been left with enough for long-term mining in its smaller area then the freeing of land for others is more than justified.
Our objective is not to give Zimplats a monopoly but to give them adequate access to the ore bodies to dig up as much as they can for many years to come; presumably if Zimplats needs more land to cope with any massive expansion they can have more. But idle land must be freed for other investors.
There are now two challenges facing Zimbabwe: how to fund expansion and how to gain maximum value from the metal. The two are related.
The three major mines -- Zimplats, Mimosa and Unki -- believe that a refinery in Zimbabwe cannot be viable until production reaches around one million ounces, roughly 31 tonnes, a year.
The very round figure suggests that this is a guesstimate, rather than the result of a detailed financial analysis, but is probably a good starting point.
The producers have their own existing refineries in South Africa so are not desperate to build a new one in Zimbabwe just yet.
But this is probably a good time to start that detailed analysis to establish the break-even point for a Zimbabwe refinery and to work out a fairly precise cost of such an investment. This does not seem to have been done yet.
The second requirement for a refinery to be viable is to ensure that all Zimbabwe platinum goes through that refinery.
This will need legal compulsion but will not only make the refinery viable sooner, but will also ensure that the refining jobs go to Zimbabweans and that all royalties and taxes are carefully calculated and collected.
At present royalties are based on trust, that accurate figures are given of the precise mass of platinum refined outside Zimbabwe.
It will be easier with our own tax collectors watching the scales.
The three initial investors are willing to discuss the refinery, but are worried that they have no idea of what new investors might be producing. We agree that these figures need to be known, in detail. New mining investors will, of course, be able to invest in the new refinery as well.
They do not lose anything by being open. In fact, our Mines Ministry should be producing detailed and accurate reports and projections freely available to anyone.
The second point about expansion is the need to mobilise Zimbabwean capital. The first stage of indigenisation was more of a "fee" to the local users of land to mine that land.
This is fine, just and help bring the companies into line with our law. But expansion will now require Zimbabwean investment equal to the foreign investment.
This can be done through stock market flotations and invitations to our pension funds. Unlike some minerals, such as diamonds or even gold, platinum enjoys steady prices and predictable demand, reducing the risks.
Zimbabweans cannot expect free lunches, only the opportunity to share in the wealth and ownership. The refinery itself will presumably require the same 50-50 investment split between external and internal investors, so that makes the business plan and cost and revenue estimates even more necessary.
So we agree that a great deal more information is now required, and that this information must be gathered, consolidated and released to the public at large; it must be prepared by technical and financial professionals, so there is no wishful thinking inserted or secrets kept.
As the data becomes available it will be possible to work out costs, viability levels and allow Zimbabwean co-investors to make sensible decisions.