[iagi-net-l] IAGI / MGEI LUNCHEON TALK_besok 14 April 2009 di Bidakara

2009-04-13 Terurut Topik benyamin sembiring
*
Topic: Myanmar Jade*

Speaker: Douglas J. Kirwin (VP Regional Affair – Society of Economic
Geologists)

Moderator: Ir. H. Sujatmiko, Dipl. Ing (Indonesian Gemologist)

Date: Tuesday – April 14, 2009; 12 a.m. – 2 p.m.

Venue: Bima Room, 2nd Floor, Bumi Karsa Hotel, Bidakara, Jakarta

Charges: IAGI/MGEI Members w/ Reservation Rp 250.000,-

Non-Members w/ Reservation Rp 275.000,-
All Walk-ins (assuming availability) Rp 300.000,-
No Shows will be charged because we must guarantee head count to restaurant
Members of other professional associations are also welcome

Contact Mobile Phone/Fax e-mail
Sutar +62 811162476 +62 21 83702848 iagi...@cbn.net.id


*ABSTRACT*
In cooperation with SEG (Society of Economic Geologists), MGEI-IAGI is
proudly arranging this luncheon talk, comparing gemstone between Myanmar and
Indonesia.
Jade has played an important cultural and economic role in Chinese society
for thousands of years. The commodity actually comprises two distinct
minerals: nephrite, which is microcrystalline mixtures of
tremolite-actinolite amphibole, and jadeitite, composed mostly of jadeitic
pyroxene. Since Neolithic times most of the production has been from
nephrite, while during the last few centuries “imperial jade”, or jadeite
has been almost exclusively sourced from northern Myanmar. Research by
Harlow et al.,(2007) demonstrates that jadeitite crystallizes from primary
fluids as vein type deposits which are generated during subduction of
oceanic crust and serpentinization of peridotites. There are 15 recorded
jadeitite global occurrences, and these primary deposits are typically small
shear-hosted lenses. The main production of jadeitite is from alluvial
deposits within ultramafic terrains, e.g. the Hpakan-Tawmaw district in
northern Mynamar. Geological mapping in British colonial times conducted by
Chhibber (1934) described tracts of jadeitite-bearing conglomerate terraces
with an areal extent of approximately 100 square kilometers and up to
200metres in thickness.The source for the jadeitite boulders are eroded
upthrust serpentinised ultramafic blocks.
Jadeitite occurs as several color varieties, depending on trace element
impurities. The emerald green color which characterizes the highly sought
after “Imperial Jade”, is due to the presence of kosmochlor (a sodium chrome
silicate). The most common colors are pale to dark green caused by iron
derived from an augite component. This is marketed as “Utility Jade”.
Jadeitite boulders from Myanmar have a brown to black weathered surface
composed of ferrihydroxides, thought to be caused by chemical reactions with
the host conglomerate matrix. This makes exploration and quality evaluation
extremely difficult. Potential buyers for high quality material risk
fortunes on boulders with indications of imperial quality The main
evaluation criteria for uncut jadeitite are color, translucence, texture,
size and, to some extent, locality. Extensive numerous opencast jadeitite
mines currently are located in the Hpakan region in Kachin state, northern
Myanmar. The scale of mines involves removal and processing of hundreds of
millions of metric tonnes from a patchwork of government issued mining
leases. The operations are now highly mechanized, utilizing fleets of large
capacity excavators. Recovery of the jadeitite boulders however, is a labor
intensive hand sorting process. The selected jadeitite boulders are then
graded and sent to Yangon for marketing. There are three to four
government-run gem auctions held annually in Yangon where 90% of revenue is
from jade sales. The auctions attract hundreds of buyers, most of whom are
asian-based Chinese. The prices for quality jadeitite, like most other
mineral commodities, have risen dramatically of the past two years, largely
fuelled by the demand from east and central Asia, including the Indian
sub-continent.
*
About the presenter: Douglas J. Kirwin*
Doug has spent more than 35 years in the mineral exploration industry, much
of which has been in the Asia-Pacific region. He is currently the
exploration executive vice-president of Ivanhoe Mines, having directed that
company's exploration activities since joining in September 1995. He was
formerly managing director of International Geological Services Pty. Ltd.
and for several years held senior positions with Anglo American and Amax. He
has evaluated mineral deposits throughout the Americas, Asia and Europe, and
has managed numerous projects in Southeast Asia and Australia.
Doug holds a Master of Science Degree in mineral exploration from James Cook
University in Australia. As a member of the joint discovery team of the Hugo
Dummett Deposit at Oyu Tolgoi, Mongolia, Doug was a co-recipient of the PDAC
inaugural Thayer Lindsley medal awarded for the most significant
international mineral discovery in 2004 and was the Society of Economic
Geologists International Exchange Lecturer for 2006. He is currently the
industry advisor for the Society of Applied Geologists, China Mining, 

Re: [iagi-net-l] IAGI / MGEI LUNCHEON TALK_besok 14 April 2009 di Bidakara

2009-04-13 Terurut Topik mohammad syaiful
dari ETTI, akan hadir 10 peserta:

1) Rizkyani
2) Intan Zalanda
3) Prasiddha
4) Deny Rahayu
5) Heidi Y. Samrosa
6) Daddy Hendarmin
7) Dwi Sriwahyuni
8) Trias Sidharta
9) Yudi Rismayana
10) Wenda Suhendar

salam,
syaiful

On Mon, Apr 13, 2009 at 3:50 PM, benyamin sembiring
benyaminsembir...@gmail.com wrote:
 *
 Topic: Myanmar Jade*

 Speaker: Douglas J. Kirwin (VP Regional Affair – Society of Economic
 Geologists)

 Moderator: Ir. H. Sujatmiko, Dipl. Ing (Indonesian Gemologist)

 Date: Tuesday – April 14, 2009; 12 a.m. – 2 p.m.

 Venue: Bima Room, 2nd Floor, Bumi Karsa Hotel, Bidakara, Jakarta

 Charges: IAGI/MGEI Members w/ Reservation Rp 250.000,-

 Non-Members w/ Reservation Rp 275.000,-
 All Walk-ins (assuming availability) Rp 300.000,-
 No Shows will be charged because we must guarantee head count to restaurant
 Members of other professional associations are also welcome

 Contact Mobile Phone/Fax e-mail
 Sutar +62 811162476 +62 21 83702848 iagi...@cbn.net.id


 *ABSTRACT*
 In cooperation with SEG (Society of Economic Geologists), MGEI-IAGI is
 proudly arranging this luncheon talk, comparing gemstone between Myanmar and
 Indonesia.
 Jade has played an important cultural and economic role in Chinese society
 for thousands of years. The commodity actually comprises two distinct
 minerals: nephrite, which is microcrystalline mixtures of
 tremolite-actinolite amphibole, and jadeitite, composed mostly of jadeitic
 pyroxene. Since Neolithic times most of the production has been from
 nephrite, while during the last few centuries “imperial jade”, or jadeite
 has been almost exclusively sourced from northern Myanmar. Research by
 Harlow et al.,(2007) demonstrates that jadeitite crystallizes from primary
 fluids as vein type deposits which are generated during subduction of
 oceanic crust and serpentinization of peridotites. There are 15 recorded
 jadeitite global occurrences, and these primary deposits are typically small
 shear-hosted lenses. The main production of jadeitite is from alluvial
 deposits within ultramafic terrains, e.g. the Hpakan-Tawmaw district in
 northern Mynamar. Geological mapping in British colonial times conducted by
 Chhibber (1934) described tracts of jadeitite-bearing conglomerate terraces
 with an areal extent of approximately 100 square kilometers and up to
 200metres in thickness.The source for the jadeitite boulders are eroded
 upthrust serpentinised ultramafic blocks.
 Jadeitite occurs as several color varieties, depending on trace element
 impurities. The emerald green color which characterizes the highly sought
 after “Imperial Jade”, is due to the presence of kosmochlor (a sodium chrome
 silicate). The most common colors are pale to dark green caused by iron
 derived from an augite component. This is marketed as “Utility Jade”.
 Jadeitite boulders from Myanmar have a brown to black weathered surface
 composed of ferrihydroxides, thought to be caused by chemical reactions with
 the host conglomerate matrix. This makes exploration and quality evaluation
 extremely difficult. Potential buyers for high quality material risk
 fortunes on boulders with indications of imperial quality The main
 evaluation criteria for uncut jadeitite are color, translucence, texture,
 size and, to some extent, locality. Extensive numerous opencast jadeitite
 mines currently are located in the Hpakan region in Kachin state, northern
 Myanmar. The scale of mines involves removal and processing of hundreds of
 millions of metric tonnes from a patchwork of government issued mining
 leases. The operations are now highly mechanized, utilizing fleets of large
 capacity excavators. Recovery of the jadeitite boulders however, is a labor
 intensive hand sorting process. The selected jadeitite boulders are then
 graded and sent to Yangon for marketing. There are three to four
 government-run gem auctions held annually in Yangon where 90% of revenue is
 from jade sales. The auctions attract hundreds of buyers, most of whom are
 asian-based Chinese. The prices for quality jadeitite, like most other
 mineral commodities, have risen dramatically of the past two years, largely
 fuelled by the demand from east and central Asia, including the Indian
 sub-continent.
 *
 About the presenter: Douglas J. Kirwin*
 Doug has spent more than 35 years in the mineral exploration industry, much
 of which has been in the Asia-Pacific region. He is currently the
 exploration executive vice-president of Ivanhoe Mines, having directed that
 company's exploration activities since joining in September 1995. He was
 formerly managing director of International Geological Services Pty. Ltd.
 and for several years held senior positions with Anglo American and Amax. He
 has evaluated mineral deposits throughout the Americas, Asia and Europe, and
 has managed numerous projects in Southeast Asia and Australia.
 Doug holds a Master of Science Degree in mineral exploration from James Cook
 University in Australia. As a member of the joint