The same as essentially every quarter minted since 1965 - twenty-five cents. Quarters dated 1965 and later are made of copper and nickel, and don't contain any silver.
Note that US Coins dated 1965-67 don't carry mint marks. The mints were operating full-bore to strike clad coins to replace the old silver ones that were rapidly being melted for their metal content. The Treasury blamed coin collectors for the shortage (to much controversy and criticism) and eliminated mint marks for 3 years to "prevent hoarding". The move had almost no effect as most hoarding was being done by speculators and not collectors.
The same as essentially every quarter minted since 1965 - twenty-five cents.
US coins didn't have mint marks from 1965 to 1967. Your coin has been altered and has no extra value.
How much is it
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A 1967 Washington quarter has no silver and is face value.
This is a novelty coin and was not made by the US Mint it has no numismatic collectible value.
Unless it's proof, it's face value. No US coins from 1965- 1967 have mintmarks.
If it is uncirculated it will be worth more than face value but if it is circulated it will be worth 25 cents.
The 1967 Washington quarter has no silver and is still in circulation, the coin is face value.
25 cents.
No US quarters were struck in silver in 1967, 1964 was the last year for silver quarters put into circulation.
A US quarter has a face value of 25 cents.
A 1765 US quarter does not exist.
There were no S-mint quarters struck from 1955 to 1967 inclusive and no US coins carried mint marks during the transition from silver to clad coinage in 1965-67.
The coins are face value and have no silver.
25 cents, unfortunately, no more.