In New York, all assets held by the parties before the date of the marriage is presumptively separate property and therefore not subject division with your spouse in a divorce.  An engagement ring or other gift given before the marriage ceremony is generally separate property.  Property acquired during a period of cohabitation before the marriage is likewise separate property.

On the other hand, a wedding ring given after the marriage vows is generally considered martial property. Wedding gifts given to both parties are generally marital property.

Separate property may be bank accounts, securities, jewelry, antiques, art, vehicles, real estate, etc.  If title to this property is held in the same manner after the marriage as before, it is likely the property will remain separate property and escape the equitable distribution of property at divorce. 

However, property, once separate, may become marital property in the event of ownership change, commingling with marital property, or other acts that cause the property to lose its separate status. Even though property may remain separate, a spouse may have a claim to distribution of the increase in value of the property attributable to the spouse's contribution.

These issues are complicated and the best course of action is to consult with an attorney.