What would be the Unicode character for big bullet in the middle of the character?

public class MyPasswordTransformationMethod extends PasswordTransformationMethod {
    @Override
    public CharSequence getTransformation(CharSequence source,View view) {
        return new PasswordCharSequence(source);
    }

    private class PasswordCharSequence implements CharSequence {
        private CharSequence mSource;
        public PasswordCharSequence(CharSequence source) {
            mSource = source; // Store char sequence
        }
        public char charAt(int index) {
            return '*'; // This is the important part
        }
        public int length() {
            return mSource.length(); // Return default
        }
        public CharSequence subSequence(int start,int end) {
            return mSource.subSequence(start,end); // Return default
        }
    }
}; 

text.setTransformationMethod(new MyPasswordTransformationMethod());