Hi Jonathan,

Thank you for contacting Mearto with your appraisal inquiry.
Yes, I thought it might be the Heisey H mark but it wasn't clear and there are a few other glass makers whose marks are letters/symbols within diamonds so I needed confirmation - thanks!
Based on the photos and information provided, and subject to examination, this is:

A vintage turtleback pressed glass charger
Made by the Heisey Company, Newark, Ohio, after 1901
Of circular section, the allover pattern a radiating web of squares, marked to the underside.
21-1/2 inches diameter
CONDITION: This glass charger appears to be in good condition; value assumes no chips, cracks or repairs.
PROVENANCE: Inherited
$ 40-60*
*represents a fair-market value for auction purposes; retail or asking price may vary.

Please let us know if you have additional items to appraise, or questions/concerns, and thank you again for using Mearto.
~ Delia