"It was five quid," she said helplessly.   Yes, it had been very pretty but at that price thinking anything else would have been insane.  It had been filthy when she'd found it, and she'd used a scouring spell on it to make it sparkle.  She'd been so pleased with herself for finding what she'd assumed was a good fake.  She'd smugly thought it was probably worth a couple of hundred pounds, a real thrifting find, and now she learned it was real diamonds instead of good imitations.  She hadn't even thought to check.