Paulb,
Got a PM from Cfmct-PI, asking me to post this list of VDIs for you. It had been posted in a previous incarnation of the forum. Hope it helps.
SOME VARIOUS COIN VDI?s
Test conditions:
Detector: Whites MXT
Coil: Whites 9.5 Concentric Stock Coil
Coins: Each coin sat in a plastic baggie during the test.
Setup: Coins were all resting flat (face up) on the dirt surface of "proven clean" ground with exactly 5? of Telephone books on top of the coin and between the coin and coil.
Actual Readings (Mean or "settled" VDI was used):
9.5? Coil Item
94 Dollar, Morgan ?Peace?
92 Half Dollar, Franklin
92 Half Dollar, Kennedy, Silver (1964)
91 Half Dollar, Standing Liberty
91 Half Dollar, Kennedy (40% Silver) 1965-1967
90 Half Dollar, Barber
89 Half Dollar, Kennedy, Silver Clad Copper
88-89 Penny, Braided Large Cent (1839-1857)
86 Quarter, Standing Liberty
85 Quarter, Washington, Silver
83 Quarter, Washington, (Clad)
82 Quarter, Barber
80 Dime, Roosevelt, Silver ?Rosie?
80 Penny, Draped Bust Cent, (1796-1807)
79 Dime, Roosevelt (Clad)
77 Dime, Mercury
77 Gold Coin, 1 oz.* (* 91% Gold, 3% Silver, & 6% alloy)
76-77 Dime, Barber
75 Two Cent Piece, Tuppence, Bronze (1864-1873)
72-74 Penny, Lincoln, Early Wheat Cent, Copper (1909-1958)
70-72 Penny, Indian Head Cent (1859-1909)
71-71 Small Cent, Flying Eagle Penny (Copper & Nickel) (1857)
72 Gold Coin, 1?2 oz.* (* 91% Gold, 3% Silver, & 6% alloy)
52 Gold Coin, 1?4 oz.* (* 91% Gold, 3% Silver, & 6% alloy)
26 Gold Coin, 1/10 oz.* (* 91% Gold, 3% Silver, & 6% alloy)
18-20 Nickel, Jefferson (Modern)
20 Nickel, Victory, "V"
18 Nickel, Early Jefferson
18 Nickel, Buffalo
8-10 Three penny, 3 Cent, Nickel/Copper (1865-1889)
These are general readings and you may find the same coin reading slightly different considering the angle of the coin in the ground, as on end or laying flat, and if that coin is near any other metal object.
Pennies: large range of VDI's depending on decomposition of the coin. Generally in the mid 70's but may range in the fifties as well. In my area they usually reads 76/77.
Nickels: 18 - 20 VDI. 90% of time you will swing one way and read 18 and the other direction a 20. This is also an excellent gold ring reading.
Dimes: 78/82 VDI
Quarters: 85 VDI I have dug a few quarters at 5-6 inches that read like a dime but they were probably laying on edge.
Silver rings will read like a dime or higher. Gold readings vary depending on size and weight. Generally speaking most gold rings/jewelry read between 8 and 20 VDI. A large class ring may read in the 50's and possibly low 60's. Large wedding sets may read in the high 20's to mid 30's. Readings from 22 - 40 are prime pull-tab readings but gold may lay there as well.
Hope this helps.