Great Britain Silver ½ Groat "Charles I Nicholas Briot's Pattern" 1640

Obverse
Large crown over rose dividing crowned monogram, engraver's initial below.
Lettering: C ∙ ∙ R ∙ B ∙

Reverse
Large crown over thistle dividing crowned monogram, date below.
Lettering: ∙ C ∙ ∙ R ∙ ∙ 1640 ∙