That's czar Nicholas II on the obverse (heads side) of these pretty gold coins. The double headed eagle of the old Byzantine Empire appears on the reverse (tails side), along with the denomination and date. Other Russian coins have Nicholas with differing reverses. This page applies only to coins that look like our picture.
The gold weight is most important when determining the value of these old Russian beauties.
5 ROUBLES, 21 mm diameter, 0.124 troy ounces gold
7.5 ROUBLES, 20 mm diameter, 0.187 troy ounces gold
10 ROUBLES, 23 mm diameter, 0.249 troy ounces gold
15 ROUBLES, 24 mm diameter, 0.373 troy ounces gold
The 7.5 and 15 rouble coins were minted only in 1897 and are very valuable. Typical values run like this:
worn: $300 US dollars
fully uncirculated: $1000
fully uncirculated: $1200
The 5 and 10 rouble denominations are much more common than the 7.5 and 15 rouble denominations. To figure their value, start with the basic gold value found by multiplying the weight of the coin by the current spot value of gold. At this writing, gold is selling around $1625 US dollars per troy ounce, so a 5 rouble coin would have a basic gold value of 0.124 x $1625 = $201 US dollars.
The value of gold changes every day. Look up the current value on sites such as kitco.com.
For 5 and 10 rouble coins that are heavily worn, scratched, cleaned, or damaged, the value will be the basic gold value. For coins that have moderate rare or better, the value is boosted by a collector premium amount. Typical collector premiums are:
average circulated: add $50 to basic gold value
fully uncirculated: add $200
average circulated: add $20 to basic gold value
fully uncirculated: add $100
In 1906 and 1907 only a small handful of these coins were minted. If you have a coin with one of these dates, and if the coin is genuine and not a counterfeit, it is worth $5000 or more.