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AG | 20oz | 25oz


ALL ENGELHARD is pleased to welcome visitors to our Johnson Matthey 20oz and 25oz Definitive Page. While our focus is clearly Engelhard, we recognize that many Engelhard bullion collectors also collect Johnson Matthey bars and ingots. As such, we appreciate the opportunity to present important bullion information on the world’s second most collectible refiner, Johnson Matthey. We hope you welcome this new addition, and we look forward to your thoughts and input!

Our Definitives, below, are organized region of origin. Also note that our Definitives reflect what we believe to be the earliest examples first, followed by more recent production examples.

IMAGE WEIGHT
CLASS
 OBVERSE REVERSE COMMENTARY SAMPLE
SERIAL
NUMBERS		 ESTIMATED
MINTAGE
unnamed20oz[Diamond JM Logo with Crossed Hammers] [20 OZ] [Serial Number] [999+] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval]Cast Finish20oz example produced by Johnson Matthey, Canada.  Considerably rare ingot, as most are believed to have been melted down during the ‘Great Melt’ period of the 1980’s.  12062 A<500
image20oz[Diamond JM Logo with Crossed Hammers] [20 OZ] [Serial Number] [999+] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval]Cast Finish20oz example produced by Johnson Matthey, Canada.  Similar to our above example, though demonstrates a letter ‘F’ serial suffix.  02136 F
02362 F
02498 F
02500 F
02543 F
02925 F
02926 F
02985 F
03047 F
03060 F
03076 F		<1100
unnamed20ozCast Finish[Diamond JM Logo with Crossed Hammers] [20 OZ] [Serial Number] [999+] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval]20oz example produced by Johnson Matthey, Canada.  Similar to our above example, though this variety demonstrates the stampings on the reverse side.03022 F<200
0-220oz[Diamond JM Logo with Crossed Hammers] [Serial Number] [999+] [20 OZ] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval]Cast Finish20oz example produced by Johnson Matthey, Canada.  Similar to our above example, though demonstrates a variation in placement of the ‘999+’ purity stamp and weight class stamp.  Our thanks to Dan S. for this discovery!  02499 F<5
FullSizeRender copy20oz[Diamond JM Logo with Crossed Hammers] [Number 8 Below Logo] [20+ OZ] [Serial Number] [999+] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval]Cast Finish20oz example produced by Johnson Matthey, Canada.  Includes unique Number 8 stamp, similar to it’s 50+oz counterpart listed on the 5oz Johnson Matthey definitive page.1178<25
unnamed20oz[Diamond JM Logo with Crossed Hammers] [20+ OZ] [Serial Number] [999+] [Number 8 Below Serial Number] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval]Cast Finish20oz example produced by Johnson Matthey, Canada.  Includes unique Number 8 stamp, similar to it’s 50+oz counterpart listed on the 5oz Johnson Matthey definitive page.  Please note that some examples demonstrate a more square casting mould and Number 8 stamp placement variations, as shown in the photo below.
image1 copy		1120
1327
1329		<50
image1 copy20oz[Diamond JM Logo with Crossed Hammers] [20+ OZ] [Serial Number] [Number 8 Below Serial Number] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval] [999+]Cast Finish20oz example produced by Johnson Matthey, Canada.  Similar to our above example, but demonstrated reverse placement of purity and small oval assay logo.1328<25
image20oz[Diamond JM Logo with Crossed Hammers] [20 OZ] [Serial Number Sideways on Right] [999+] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval]Cast Finish20oz example produced by Johnson Matthey, Canada.F003629
F004648
Foo4766
<1,500
Screenshot 2024-07-25 at 3.02.13 PM20oz[Simmons Refining Company Large ‘S’ Hallmark]  [REFCO METALS] [999+] [20 OUNCES TROY] [Serial Number] [ASSAYERS] [Simmons Refining Company Small ‘S’ Hallmark]  [REFINERS]Cast Finish20oz class ‘Type E’ ingot produced by Simmons Refining Company.   This example was produced from a 20oz Johnson Matthey casting mould and includes the JM style serial number font stamping.F000027<50
MINTAGE
unnamed-120oz[Diamond JM Logo with Crossed Hammers] [20 OZ] [999+] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval]Cast Finish20oz example produced by Johnson Matthey, Canada.  This ‘Small Diamond’ variety is considerably more rare than the ‘Large Diamond’ variety.  We believe the ‘0007’ serial number on the example below was applied post-produciton.
unnamed		Serial Absent<100
JM 20oz 20oz [JOHNSON MATTHEY] [Diamond JM Logo with Crossed Hammers] [Serial Number Sideways on Left] [20] [999+] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval] Cast Finish
 20oz example produced by Johnson Matthey, Canada.  Some examples are observed with opposite placement of the serial number.  Interesting to note that example F006352 demonstrates reverse stamp impression anomaly on the ingot’s reverse, pictured below.  Although the serial number range for this 20oz variety suggests a significant production mintage, these examples are seldom available on public auction.
unnamedOf further interest is the discovery of duplicate serial number F007052, a very rare happenstance and  presented below.
s-l1600		 F002719
F003752
F004218
F005269
F005334
F006352
F007052
F008096
 <7,500
thumbnail 220oz[JOHNSON MATTHEY] [Diamond JM Logo with Crossed Hammers] [20 OZ] [Serial Number Sideways on Right] [999+] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval]Cast Finish20oz example produced by Johnson Matthey, Canada.  Similar to our above example, though demonstrates serial placement variation and earlier series weight stamp.F004856
F004992		<100
IMG_247220oz[JOHNSON MATTHEY] [Diamond JM Logo with Crossed Hammers] [20 OZ] [Serial Number Sideways on Right] [999+] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval]Cast Finish20oz example produced by Johnson Matthey, Canada.  Similar to our above examples, though demonstrates serial placement variation and earlier series weight stamp.F003025<100
thumbnail (3)20oz[TD Bank Logo] [Serial Number] [20 OZ] [999+] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval]Cast Finish20oz example produced by Johnson Matthey, Canada, for TD Bank. F006820<250
JM_20Oz_TDBankObv20oz[TD Bank Logo] [Serial Number Sideways on Left] [20 OZ] [999+] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval]Cast Finish20oz example produced by Johnson Matthey, Canada, for TD Bank.
F008196
F008270
F008534		<500
unnamed20oz[Diamond JM Logo with Crossed Hammers] [20 OZ] [999+] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval]Cast Finish20oz example produced by Johnson Matthey, Canada. Serial absent variation with ‘Large Diamond’ hallmark.  It is of interest that the majority of ingots observed in this particular variety have been attractive examples of  relatively high production quality.  Note at least one example demonstrates an inverted weight stamp, as shown below.
image0-3		Serial Absent<2,000
unnamed20oz[20 OZ] [999+]Cast Finish20oz example produced by Johnson Matthey, Canada.  Similar to our example above, though lacks the Johnson Matthey ‘Large Diamond’ hallmark and smaller ‘Oval Logo’ designation.Serial Absent<5
unnamed20oz[Diamond JM Logo with Crossed Hammers] [20 OZ] [999+]Smooth Finish20oz example produced by Johnson Matthey, Canada.  Unique example in that the stampings have been applied to the flat reverse side, note the absence of the small oval JM hallmark typically applied next to the purity stamp. Serial Absent<5
unnamed20oz[Diamond JM Logo with Crossed Hammers] [20 OZ] [999+] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval]Smooth Finish20oz example produced by Johnson Matthey, Canada.  Similar to our example directly above, the stampings have been applied to the flat reverse side.  However, this example includes the small oval JM hallmark applied next to the purity stamp. Serial Absent<750
image20oz[Diamond JM Logo with Crossed Hammers] [20 OZ] [CANADA Inner Oval] [JM LTD. ASSAY OFFICE Oval Logo] [999+]Cast Finish20oz example produced by Johnson Matthey, Canada. Serial absent variation.  Note the opposite placement of purity and assay stampings as opposed to our entry directly above.Serial Absent<500
image220oz[Diamond JM Logo with Crossed Hammers] [20 OZ] [CANADA Inner Oval] [JM LTD. ASSAY OFFICE Oval Logo] [999+]Cast Finish20oz example produced by Johnson Matthey, Canada. Similar to our above example, though demonstrates a tighter spacing between the purity numbers.Serial Absent<250
IMG_417920oz[Diamond JM Logo with Crossed Hammers] [20 OZ] [CANADA Inner Oval] [JM LTD. ASSAY OFFICE Oval Logo] [999+]Cast Finish20oz example produced by Johnson Matthey, Canada.  This example was produced from the same casting mould as the Johnson Matthey 1/2 Kilo ingots, as well as the Number 8 stamped examples presented on this page.   Serial Absent<50
unnamed20oz[Diamond JM Logo with Crossed Hammers] [Number 8 Below Diamond Logo] [20 OZ.TR] [CANADA Inner Oval] [JM LTD. ASSAY OFFICE Oval Logo] [999+]Cast Finish20oz example produced by Johnson Matthey, Canada.  This example is noteworthy in that it demonstrates a serial number and the unique Number 8 stamp.1123
1139		<25
unnamed-120oz[Diamond JM Logo with Crossed Hammers] [20 OZ.TR] [CANADA Inner Oval] [JM LTD. ASSAY OFFICE Oval Logo] [999+]Cast Finish20oz example produced by Johnson Matthey, Canada. Serial absent variation and OZ.TR weight suffix.Serial Absent<250
image20oz[Diamond JM Logo with Crossed Hammers] [20 OZ.TR] [999+] [CANADA Inner Oval] [JM LTD. ASSAY OFFICE Oval Logo]Cast Finish20oz example produced by Johnson Matthey, Canada. Similar to our above example but demonstrates reverse placement of purity and oval logo.Serial Absent<25
unnamed copy20oz[Diamond JM Logo with Crossed Hammers] [20 OZ.TR} [CANADA Inner Oval] [JM LTD. ASSAY OFFICE Oval Logo] [999+]Cast Finish20oz example produced by Johnson Matthey, Canada. Similar to our above examples but demonstrates the smaller JM Diamond Hallmark.  Serial Absent<10
image20oz[Diamond JM Logo with Crossed Hammers] [20 OZ.TR] [999+] [CANADA Inner Oval] [JM LTD. ASSAY OFFICE Oval Logo]Cast Finish20 oz example produced by Johnson Matthey, Canada. Similar to the above example with the smaller JM Diamond Hallmark, but the purity and the oval JM assay stamp are reversed. This example sold for $1,450.00 on January 22, 2018.Serial Absent<10
unnamed20oz[JOHNSON MATTHEY & MALLORY Oval Logo] [CANADA Inner Oval] [20 OZ.TR] [999] [J M & M LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval]Cast Finish20oz example produced by Johnson Matthey & Mallory, Canada.  Unique placement of weight class designation and purity stamp lacks the ‘+’ on 999 fineness.Serial Absent<25
IMG_981820oz[JOHNSON MATTHEY & MALLORY Oval Logo] [CANADA Inner Oval] [20 OZ.TR] [J M & M LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval] [999]Cast Finish20oz example produced by Johnson Matthey & Mallory, Canada.  Similar to our above example, though with reverse placement of purity and smaller oval logo.Serial Absent<25
58259626336__C96ECFEB-A993-4B1F-8CB2-DE01017D8FDE20oz[JOHNSON MATTHEY & MALLORY Oval Logo] [CANADA Inner Oval] [20 OZ.TR] [999+] [J M & M LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval]Cast Finish20oz example produced by Johnson Matthey & Mallory, Canada.  Unique placement of weight class designation and purity stamp includes the ‘+’ on 999 fineness.Serial Absent<10
image20oz[JOHNSON MATTHEY & MALLORY Oval Logo] [CANADA Inner Oval] [J M & M LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval] [999+] [20 OZ.TR]Cast Finish20oz example produced by Johnson Matthey & Mallory, Canada.  Note the spectacular cooling lines and toning on the example pictured.Serial Absent<250
image20oz[JOHNSON MATTHEY & MALLORY Oval Logo] [CANADA Inner Oval] [Maple Leaf Logo] [999+] [20 OZ.TR]Cast Finish
20 oz example produced by Johnson Matthey & Mallory, Canada. Similar to
the above example but lacking the second smaller oval JM&M hallmark.
Serial Absent<25
JM_20Oz_PouredNoSerialObv 20oz [JOHNSON MATTHEY & MALLORY Oval Logo] [CANADA Inner Oval] [Maple Leaf Logo] [J M & M LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval] [999+] [20 OZ.TR] Cast Finish
 20oz example produced by Johnson Matthey & Mallory, Canada.  This example is more of a ‘pudgy’ shape than the one listed above and also demonstrates a different oval hallmark and includes the Maple Leaf logo.  Other varieties are flatter and wider/longer than this unique ingot. Serial Absent <25
unnamed20oz[JOHNSON MATTHEY & MALLORY Oval Logo] [CANADA Inner Oval] [J M & M LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval] [999+] [20 OZ.TR]Cast FinishSimilar to our ‘pudgy’ example above example, but does not include the Maple Leaf logo.  Other varieties are flatter and wider/longer than this unique ingot.Serial Absent<25
20180730_113642 copy20oz[JOHNSON MATTHEY & MALLORY Oval Logo] [CANADA Inner Oval] [J M & M LTD. ASSAY OFFICE Oval Logo] [20 OZ.TR] [999+]Cast FinishSimilar to our  above example, but does not include the smaller JM&M Oval Logo.Serial Absent<25
image20oz[JOHNSON MATTHEY & MALLORY Oval Logo] [CANADA Inner Oval] [J M & M LTD. ASSAY OFFICE Oval Logo] [20 OZ.TR] [999+]Cat FinishSimilar to our two ‘pudgy’ examples above example but does not include the Maple Leaf logo or the smaller oval hallmark.  Other varieties are flatter and wider/longer than this unique ingot.  Sales record of the only known example reflects purchase price of $1,398.42 on May 23, 2017.Serial Absent<25
image20oz[JMC Rectangular Logo] [999+] [20oz.TR]Cast Finish20oz example produced by Johnson Matthey & Mallory, Canada.  This variety, and the one directly below with the Maple Leaf Logo, are the only known variety of JMC ingot to have been cast from the same size mould as our three ‘pudgy’ JM&M portrait examples listed above.Serial Absent<100
1530977142097-178068859220oz[JMC Rectangular Logo] [999+] [Maple Leaf Logo] [20oz.TR]Cast Finish20oz example produced by Johnson Matthey & Mallory, Canada.  Similar to our above example, but includes the Maple Leaf Logo.Serial Absent<25
JM 20oz LONDON20oz[JOHNSON MATTHEY LONDON Oval Logo] [REFINERS MELTERS Inner Oval] [999] [20 OZS]
Cast Finish20oz example produced by Johnson Matthey London.  At least one known example demonstrates a waffle finish on the reverse, pictured below.
Screen Shot 2017-10-20 at 12.53.01 PM		Serial Absent<200
FullSizeRender25oz[SONY ®] [25 YEARS] [&] [WACKID RADIO] [25 OZ] [SERIAL NUMBER] [999+] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval]Cast Finish25oz example produced by Johnson Matthey, Canada for SONY and Wackid Radio, a supplier of SONY Professional Products.SO11<25
admin-ajax.php25oz[Diamond JM Logo with Crossed Hammers] [25 OZ] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval] [999+]Cast Finish25oz example produced by Johnson Matthey, Canada.  Large weight class designation font, earliest known variety.Serial Absent<10
unnamed 25oz [Diamond JM Logo with Crossed Hammers] [25 OZ] [Serial Number] [999+] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval] Cast Finish
 25oz example produced by Johnson Matthey, Canada. 19914E
20017E		 <25
s-l160025oz[Diamond JM Logo with Crossed Hammers] [25 OZ] [Serial Number] [999+] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval]Cast Finish25oz example produced by Johnson Matthey, Canada.E020077<25
FullSizeRender 225ozDiamond JM Logo with Crossed Hammers] [25 OZ] [999+] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval]Cast Finish25oz example produced by Johnson Matthey, Canada. Serial absent variation of our example above.
Serial Absent<25
image25ozDiamond JM Logo with Crossed Hammers] [25 OZ] [999+] [JM LTD. ASSAY OFFICE Oval Logo] [CANADA Inner Oval]Cast Finish25oz example produced by Johnson Matthey, Canada. Serial absent variation of our example above with font anomaly on weight stamp.  Notice the smaller ‘5’ in the ’25oz’ weight class designation.Serial Absent<25
 

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