THE FORMATION OF QUEENSLAND
SAPPHIRE RESOURCES - AN ALTERNATIVE THEORY!
Taken from an address by Jim
Elliot at the Central Queensland Gemfest 2003
The conventional theory has it
that the formation of the Central Queensland and the Lava Plains
sapphire resources is the result of major extrusions or
emissions from large volcanic sources and that the sapphire was
subsequently transported by large river systems and deposited in
the areas where it is currently mined today.
As a result of observations
during some 20 years of mining on the Central Queensland
Gemfields and 5 years on the Lava Plains field, I believe this
theory to be totally incorrect.
I believe that the sapphire was
produced from a large number of smaller vents which are located
throughout the sapphire producing areas, and that the sapphire
never moves, any significant distance from its point of origin
at the surface.
I believe that the term ''water
worn sapphire" and, to a large extent, "water worn billy
boulders and rocks" are similarly incorrect and that any wearing
or rounding took place in the process of formation, and not as a
result of alluvial transportation.
I provide the following
information in support of my theory and as reasons why I found
it necessary to look for a different method of formation than
the one which has been generally accepted in the past.
a. We have found
tremendous variation in the quality and nature of not only the
sapphire within very short distances, but also of the associated
ironstone and silcrete (billy boulders).
b. When trying to follow
the "sapphire river system" in any area, we found that :: were
constantly coming out of one type of mining terrain and going
into other where the inherent characteristics of the material
c. We found as many as
three overlying wash layers with totally different types of
sapphire and ironstone, and the directions of deposition varied
widely and could not be related to surrounding areas.
d. We started to mine at
Lava Plains, our preconceived ideas failed us and we had
difficulties in locating and understanding the sapphire
deposition and formation patterns
We tried some mining techniques
which would have had conventional miners questioning our sanity
- but they worked, and we found sapphire! We left the
alluvial systems and started mining the huge deposits of
volcanic ash which blanket the area - and we found excellent
We stripped off layers of lava
flow rock to expose further layers of volcanic ash below - and
again we found more sapphire.
We then moved away from the
small source vents which produced the material and the quantity
and quality of sapphire decreased quite quickly as we moved away
- despite the presence of significant alluvial beds, so the
river transportation theory was losing its appeal to us.
We then moved back to the
alluvial beds in the area closer to the vent sources, and found
bulk Sapphire - but again the quality varied quite quickly when
we moved from one vent area to another even though they were
only a few hundred metres apart.
We came back to the C.Q. Gemfields and looked at our mining in a
new light, looking for evidence of small localised deposits -
and the evidence was everywhere.
f. We looked at the
current major river systems like Retreat Creek, which flows past
the major volcanic peaks which we had always been told were the
source of all our sapphire.
However, when one analysed the
sapphire from the various mining areas down the course of
Retreat Creek, the material had distinct changes at least 6
times in the length of flow through the Gemfields area.
Having thought about all these
variables, and with my trusty divining rods in hand, I went back
over many of the mining areas which-had been "worked out"
as a result of the mining over the 125 years of the field's
I identified many, many small
source vents, and it became apparent that many of these vents
must have had several stages of production and that, as a
result, there would be several layers of wash from the one
source in many cases.
This enabled me to direct some
hardworking hand miners into areas which older hands said were
totally mined out - but the current hand miners have gone
further down and found good, bearing wash as a reward for their
I provide some thoughts on
currently held ideas for consideration by learned and qualified
geologists and gemologists..
1. "Water Worn Sapphires"
Every rockhound knows that if
you put a sapphire crystal in a tumbling machine with grinding
compound and let it run for even I0 weeks the sapphire will
probably still have it's corners still visible. If you do the
sum for a 500mm diameter tumbler doing 40 revs per minute, for
60 mins/hour, 24 hrs/day, 7days/week, for 10 weeks - you will
find that your sapphire has traveled some 6,000 kilometres in a
dry abrasive environment - but is still not reduced to a round
How is it formed then? I
believe that the pebble is formed by the rounding of the
sapphire crystal in the vary high temperature and the very
aggressive environment in the 'formation tube' during the
passage from the formation zone some 65 kilometres below the
It will be noticed that many of
these rounded sapphire pebbles have a surface which is severely
pitted with small pinhole craters - whereas, if they were stream
worn they would have smooth surfaces.
This pitting is the result of
the explosion of small dots of rutile just below the surface of
the sapphire crystal. It the temperature is below the melting
point of sapphire, but above the volatilisation point of rutile,
the escape of the volatilised rutile will pit the softened
surface, but rutile further below the surface will be captured
by the skin tension and will be absolved or reconverted within
2. "Water Worn" Billy
I do not believe that the
smooth surface of billy boulders is due to any form of stream
polishing, but is again the result of rounding and glazing in
the aggressive 'formation tube' environment.
Every miner has seen billy
boulders with holes right through them and with deep crevices
and holes - and they are always polished, even in these hard to
get at locations - so this cannot be from stream wear.
3. Shape of Sapphire
Conventional wisdom has it that
sapphire forms in the shape of double-terminated "dogs teeth",
or at very least a single dogs tooth form.
Having studied tens of
thousands of pieces of sapphire from out mining operations,
Jenny can assure you that very little of the sapphire found is
actually broken, and that most of the pieces actually are the
entire crystal as it was formed.
This "as formed" crystal shape
can be chunky, but irregular, or flat like a sapphire platelet -
but they all are fully developed crystals without being broken
off a larger piece. Many miners, when finding a large piece
which is apparently the broken-off centre section of a dogs
tooth have been known to exclaim that they wish that they could
find the rest of the crystal - when , in reality, they do have
the entire crystal.
While many people believe will
undoubtedly say "who cares?", we believe that the proper
recognition of the formation and type of sapphire is relevant
and important for the survival and development of our industry.
If new miners look at many of
the old "mined out" 6reas in an un-prejudiced light, I believe
that they will find that there are still very large reserves of
sapphire to be tapped - not only on the existent sapphire mining
areas, but throughout the rest of Australia.
These as-yet undiscovered new
areas of commercial significance may not be of the same scale as
New England, Central Queensland or Lava Plains - but they will
each have their own characteristics and could well play a major
part in both the recognition and the marketing of Australian
Australian sapphire has
suffered in the past because of the domination of the world
markets, principally by the Thai dealers and factories. As a
direct result of their deceitful practices in taking the major
portion of our rough back to Thailand for heat treatment and
cutting, and later reselling the best of our sapphire as being
"Thai" or "'Ceylon" sapphire, the world has not been allowed to
recognise the true high quality and amazing colour range of
This Thai domination is rapidly
coming to an end, and the rapid collapse of their control is
largely due to their own continuation of deceitful practices.
The selling of huge amount of chemically modified beryllium
treated sapphire to unsuspecting regular clients without telling
them what the material really was, has destroyed a lot of
confidence in the Thai cutting industry.
Australia now has a great
opportunity to be recognised finally as a major world player in
the sapphire industry - as a supplier of high quality, genuine,
natural, unadulterated material.
genuine sapphire -
made by nature
Resource on the Australian Sapphire Industry