Tables for 9ct, 18ct Gold Content, Chain Lengths and Ring Sizes.

TROY OUNCE DEFINITION

1 Troy Ounce = 31.1035 grams     
1 Ounce pure Gold = 31.1 grams 24 ct (0.9999%)     
     
1 Ounce (1 Troy) 9ct gold bracelet weighing 31.1gms     
contains (9/24)*31.1 = 11.66gms pure gold     
Therefore (30.1 - 11.66) = 19.44 grams in every Troy Ounce is not gold 

GOLD CONTENT

Gold Content by see-search.com
GOLD       Parts/1000  Gold Content / Troy oz 
  9ct                    375                  11.66 gms
  14ct                  585                  18.14 gms
  18ct                  750                   23.33 gms
  22ct                  916                   28.51 gms
  99% pure          990                   30.79 gms
  99.9% pure       999                   31.07 gms
  24ct 100%       1000                   31.104 gms 

CHAIN LENGTHS

CHAIN LENGTHS by see-search.com
Inch     cm      Comment
  16        41       Short Chain for Pendants
  18        46       Standard Ladies, Small Gents
  20        51       Long Ladies, Standard Gents
  22        56       Long Pendant and Lockets
  24        61       Long
  28        71       Very Long
  30        76       Extra Long

RING SIZES

RING SIZES by see-search.com
 UK        mm Dia    mm Circ          US
  A            11,5           36,25               0.5
  B            12,3           38,64               1
  C            12,7           39,9                 1.5
  D            13,1           41,15               2 
  E            13,5           42,41               2.5 
  F            13,9           43,67               3
  G            14,3           44,92               3.25
  H            14,7           46,18               3.75
  I             15,1           47,44               4.25
  J             5,5            48,69                4.75
  K            5,9            49,95                5.25
  L            16,3           51,24               5.75
  M           16,7           52,46               6.25
  N           17,1            53,72               6.75
  O           17,5            54,98               7
  P           17,9            56,23               7.5
  Q           18,3            57,49               8
  R           18,7            58,75               8.5
  S           19,1            60,0                9
  T           19,5            61,26               9.5
  U           19,9            62,52              10
  V           20,3            63,77              10.5
  W          20,7            65,0                11
  X            21,1            66,29             11.5
  Y           21,5             67,51             12
  Z           21,9             68,77              12.5

GOLD SILVER PLATINUM HALLMARKS

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