ARIZONA ASSAY OFFICE

ALL ENGELHARD is pleased to welcome visitors to our Arizona Assay Office Definitive Page. While our focus is clearly Engelhard, we recognize that many Engelhard bullion collectors also collect other bars and ingots. As such, we appreciate the opportunity to present additional collections and look forward to your thoughts and input!

Arizona Assay Office ingots were never considered part of the ‘Franklin Hoard’ and initially appeared at the same time as the Star Mining and F.G. Hoard gold ingots. They were modern issue examples produced in late 1969 by Jack Stone out of his North First Street location in Phoenix, Arizona, primarily for distribution by Paul Franklin. Franklin had recently returned from an extended trip abroad and was the distributor for the Jack Stone Arizona Assay Office ingots through his new company, Arizona Silver Company. Stone wrote an introductory letter on Arizona Assay Office letterhead certifying his manufacturing of these examples. There was not any cover up story associated with these pieces, and they were of the genre of the numerous private silver ingots before the ‘Art Bar Craze’ of the early 1970’s.

These examples were produced in total mintage of 80 and in varying fineness of .720, .900, .925, .963, .999 and .9995 purity. The .725 and .925 examples are similar to each other in casting size, but are distinctly different than the other examples. Additionally, the .995 and .999/.9995 examples were produced using two different casting moulds, with ingots S454 and S456 being of a larger and more shallow casting mould than the other examples. A few unique copper examples were also produced, and are presented within this page among their silver counterparts.

There are currently fewer than 50 known Arizona Assay Office examples, at least 12 of which demonstrate a single border ring hallmark stamp. We present the only known gold example first, directly below, followed by the silver examples.

EXAMPLE	OBVERSE	REVERSE	COMMENTARY	KNOWN WEIGHT CLASS	KNOWN SERIAL NUMBERS	ESTIMATED MINTAGE
	[999 FINE] [Weight Class] [Serial Number] [Double Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479]	[Single Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479]	Approximate 6oz class gold bar produced by Arizona Assay Office.	5.81oz	0536	<5
	[Serial Number] [Double Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479] [999 FINE] [Weight Class]	Pressed Finish	Approximate 3oz class gold bar produced by Arizona Assay Office.	3.34oz	N/A	<5

EXAMPLE	OBVERSE	REVERSE	COMMENTARY	KNOWN WEIGHT CLASS	KNOWN SERIAL NUMBERS	ESTIMATED MINTAGE
	[Double Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479] [925 FINE] [Weight Class] [OZS.]	Pressed Finish	1oz class bar produced by Arizona Assay Office. This are a very thin and sheet-like bar.	.86oz	76 [.925 FINE]	<5
	[Double Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479] [999 FINE]	Cast Finish	1oz class ingot produced by Arizona Assay Office. Ingots B101 and B104 have the weight and purity stamps on the reverse of the ingot.	1.87oz 1.90oz	B101 [.999 FINE] B104 [.999 FINE]	<5
	[Double Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479] [.999 FINE] [Weight Class] [OZS.] [Serial Number]	Cast Finish	1oz class ingot produced by Arizona Assay Office in .999 purity.	1.71oz	356 [.999 FINE]	<5
	[Double Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479]	Cast Finish	Approximate 2oz class ingot produced by Arizona Assay Office. This unique piece measures approximately two inches in width by approximately one inch in height. It lacks purity, weight and serial number assignment stampings.	2.49oz	Serial Absent	<5
	[Double Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479] [999] [FINE] [Weight Class] [OZS] [Serial Number]	Cast Finish	Approximate 3oz class ingot produced by Arizona Assay Office with occasional serial number ‘B’ or ‘S’ prefix and ‘S’ suffix on the purity stamp. Note the varying purity noted in the serial number examples column. Ingot 999 demonstrates supplemental weight stampings on the reverse as shown below, and sold via eBay auction on October 15, 2019.	2.88oz 3.13oz 3.29oz 3.37oz 3.42oz 3.42oz 3.52oz 3.58oz 3.61oz 3.67oz 3.69oz 3.76oz 3.79oz 3.83oz 3.86oz 3.87oz 3.89oz	999 [.925] 1101 [.999] 1099 [.999] 1058 [.999] 1074 [.995] 1190 [.999S] 1221 [.999S] 1027 [.999] 1066 [.999] S454 [.999] B1427 [.900] S456 [.999] 1220 [.999S] 1059 [.999] 1072 [.999] 1075 [.9995] 1068 [.999]	<25
	[Double Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479] [999] [C] [FINE] [Weight Class] [OZS.] [Serial Number]	[Letter ‘C’ repeated seven times]	Approximate 3oz class copper ingot produced by Arizona Assay Office. Note the ‘C’ designation on the obverse and reverse, denoting the copper composition. Likely a prototype example, the casting mould measures wider from left to right and is shallower than its silver ingot counterparts.	2.67oz	103 [.999]	<5
	[Weight Class] [OZS] [s925] [FINE] [Serial Number] [Double Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479]	Cast Finish	Approximate 3oz class ingot produced by Arizona Assay Office in exceedingly rare portrait variation and .925 purity. This example is quite unique in that it appears to have been stamped on the reverse vs. obverse as observed on other Arizona Assay Office ingots.	3.75oz	104 [.925]	<5
	[Double or Single Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479] [999] [FINE] [Weight Class] [OZS] [Serial Number]	Cast Finish	Approximate 5oz class ingot produced by Arizona Assay Office with occasional serial number ‘M’ prefix or serial number ‘B’ suffix. Some examples also include an ‘S’ prefix or suffix on the purity stamp. Observed in either single or double circular Arizona Assay Office hallmark and in varying purity. Ingot 1031 sold via auction in May, 2019 for $2,225.00. Note the casting mould size difference between many of these ingots, as demonstrated in the photo below.	4.20oz 4.24oz 4.35oz 4.68oz 4.72oz 4.74oz 4.73oz 4.79oz 4.80oz 4.89oz 4.92oz 5.11oz 5.30oz 5.34oz 6.14oz 6.94oz	1076 [.9995] 1031 [.999] 1082 [.9995] 1150B [.925] 1163 [.925] 1087 [.9995] 1081 [.9995] 1109 [.999] 1160S [.925] 1179 [S.999] 1005 [.999] M21 [.720] 1114 [.999] M22 [.720] 1011 [.925] 1180 [.999S]	<25
	[Single Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479] [900] [FINE] [Weight Class] [OZS] [Serial Number]	[Weight Class] [FINE]	Approximate 5oz class ingot produced by Arizona Assay Office with serial number ‘S’ prefix and 5.12oz weight stamp on the reverse for actual fine silver content.	5.12oz	S1427 [900]	1
	[Single Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479] [999S] [FINE] [Weight Class] [OZS] [Serial Number]	[Double Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479]	Approximate 5oz class ingot produced by Arizona Assay Office. Note the single circular outline on the obverse Arizona Assay Office Hallmark and the double circular outline on the reverse.	6.38oz	1206 [.999S]	1
	[Double Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479] [999] [FINE] [Weight Class] [OZS] [Serial Number] [Custom Flower Stamp]	[★ A.M.CO. ★] [★ 999 ★]	5oz class ingot produced by Arizona Assay Office. Similar to our example above, but includes A.M.CO. counterstamp on the reverse. This is the only known even 5oz ingot in this weight class and we believe at this time that the A.M.CO. reverse counterstamp was applied at the time of production.	5.00oz	499 [.999]	1
	[SILV.] [Single Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479] [999] [FINE]	Cast Finish	Approximate 5oz class ingot produced by Arizona Assay Office in exceedingly rare portrait variation.	4.76oz	Serial Absent	1
	[999] [FINE] [Double Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479] [AN. CO.] [GR 164]	[57]	Approximate 5oz class copper/silver alloy ingot produced by Arizona Assay Office. This unique bi-metal ingot assay tested at 50% pure copper and 50% fine silver. We have confirmed that Arizona Assay Office was contracted to refine copper and silver for the Copper Gossan Claim Group in 1965. It is of the same casting mould as ingots 4.89oz #1179 and 6.94oz #1180. Ingot PD 57 sold via eBay auction on December 13, 2019 for $2,733.50. A sizing comparison is provided in the photos for similar ingot PD 60 directly below.	5.27oz	57	1
	[999] [FINE] [Double Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479] [PD] [60]	Cast Finish	Approximate 5oz class copper/silver alloy ingot produced by Arizona Assay Office. Similar to our entry directly above, this bi-metal ingot assay tested at 50% pure copper and 50% fine silver. We have confirmed that Arizona Assay Office was contracted to refine copper and silver for the Copper Gossan Claim Group in 1965. It is of the same casting mould as ingots 4.89oz #1179 and 6.94oz #1180. A sizing comparison is provided in the photos below.	5.04oz	PD 60	1
	[Double Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479] [999 FINE] [Weight Class] [OZS.] [Serial Number]	Cast Finish	Approximate 6oz class ingot produced by Arizona Assay Office with double circular outline on the Arizona Assay Office Hallmark. This ingot is of a unique casting mould and sold via auction in May, 2019 for $3,643.95.	6.17oz	1041 [.999]	<5
	[Single Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479] [999] [FINE] [Weight Class] [OZS] [Serial Number]	Cast Finish	Approximate 10oz class ingot produced by Arizona Assay Office. Note the single circular outline on the Arizona Assay Office Hallmark.	9.21oz 10.43oz	S518 [.999] S516 [.999]	<5
	[Single Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479] [S963] [FINE] [G] [Weight Class] [OZS]	Cast Finish	Approximate 10oz class ingot produced by Arizona Assay Office. Note the single circular outline on the Arizona Assay Office Hallmark and the ‘G’ prefix on weight class stamp. This ingot does not include a serial number.	11..57oz	Serial Absent [.963]	1
	[Single Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479] [925] [FINE] [Weight Class] [OZS.] [Serial Number]	[Weight Class] [FINE] [OZS.]	Approximate 15oz class ingot produced by Arizona Assay Office. Note the single circular outline on the Arizona Assay Office Hallmark and 14.52oz weight stamp on the reverse for actual fine silver content.	14.52oz	S1176 [.925]	<5
	[Single Circular Arizona Assay Office Hallmark] [★ ARIZONA ★ ASSAY OFFICE] [Outline of Arizona] [REG No. 5479] [Serial Number] [999+] [FINE] [OZS.] [Weight Class]	Cast Finish	20oz class ingot produced by Arizona Assay Office, largest known weight class from this refiner. Note the single circular outline on the Arizona Assay Office Hallmark. This ingot is the largest known weight class and is the only Arizona Assay Office piece known to include a ‘+’ after the purity stamp and demonstrate a leading zero serial number. There is a C. Rhyne hallmark over-stamped on Arizona Assay Office hallmark, pictured below. This ingot is understood to have at one time been a part of the Craig Rhyne & associates precious metals holdings.	20.00oz	0385 [.999+]	<5