Final answer:
The detail that best helps visualize the setting describes 'intricate symbols carved into the sparkling black stone,' as it includes specific imagery.
Step-by-step explanation:
The detail from the passage that best helps the reader picture the setting is "I looked closely and saw intricate symbols carved into the sparkling black stone." This selection contains vivid descriptive language that stimulates the reader's visual imagination, allowing them to create a clear picture of the setting in their mind. It mentions 'sparkling black stone' and 'intricate symbols', which are specific and imagery-rich details that contribute to building the setting.