One must consider that by 'discovered' you mean by humans.
Since it is not possible to communicate with animals or geographies, we cannot know how diamonds were regarded, considered, acknowledged -- or used -- before being discovered by humans.
gold and diamonds.
Diamonds have been part of human history for about 6,000 years.
no tylor stephenson did Rubber was in use in Central America before Europeans went there. I don't know if it was the Incas who first used it.
Prehistory.
From Wikipedia: "The history of diamond cuts can be traced to the late Middle Ages, before which time diamonds were enjoyed in their natural octahedral state-anhedral (poorly formed) diamonds simply were not used in jewelry. The first 'improvements' on nature's design involved a simple polishing of the octahedral crystal faces to create even and unblemished facets, or to fashion the desired octahedral shape out of an otherwise unappealing piece of rough." You can read more about the cut of diamonds, below.
yes, probably lots, like in diamonds we haven't discovered.
To date, no raw diamonds have been discovered in the geography of New Zealand.
Back in 1867 diamonds were used as adornment, since the application of industrial diamonds had not truly evolved at that time. In fact, for the roughly 6,000 years before today, people have used diamonds as adornment.
No country is in the diamond discovery business. However, humans have discovered diamonds on every continent except Europe and Antarctica.
Diamonds have been part of human history for more than 6,000 years.
The Crater of Diamonds State Park in Arkansas sits on land historically used as farmland. You can read its history, below.
diamonds
nothing
Cellulose
what was electricity used for when it was dicovered
Since not all diamonds have been discovered, it is not possible to give you the answer you want.
yes. In the modern processes of making man-made diamonds, it has been found that impurities in the output are reduced when (tiny) diamonds are used as the feedstock rather than graphite as had been used before. see diamonds in wikipedia.org