| Oxide | Content in wt% |
| SiO2  | 62.8+-0.3      |
| Na2O  | 18.2+-0.2      |
| CaO   | 7.8+-0.1       |
| B2O3  | 4.9+-0.1       |
| MgO   | 3.5+-0.1       |
| Al2O3 | 1.8+-0.1       |
| K2O   | 0.8+-0.1       |

Caption: Chemical composition of the melt (= basic glass melt)

You are provided with a table from a material science paper. Here are JSON templates for two types of numeric cells: "Other" and "Glass_Compound_Amount":
{"value": "xx", "type": "Other"}
{"value": "xx", "type": "Glass_Compound_Amount", "constituent": "xx", "unit": "xx", "material": "xx"}

Please describe all numeric cells in the above table following the JSON templates (proceeding by row in a left-right, top-down direction). For each cell, output one JSON description per line. For any unanswerable attributes in the templates, set their value to the placeholder "xx".

Cell Description:
{"value": "62.8", "type": "Glass_Compound_Amount", "constituent": "SiO2", "unit": "wt", "material": "xx"}
{"value": "18.2", "type": "Glass_Compound_Amount", "constituent": "Na2O", "unit": "wt", "material": "xx"}
{"value": "7.8", "type": "Glass_Compound_Amount", "constituent": "CaO", "unit": "wt", "material": "xx"}
{"value": "4.9", "type": "Glass_Compound_Amount", "constituent": "B2O3", "unit": "wt", "material": "xx"}
{"value": "3.5", "type": "Glass_Compound_Amount", "constituent": "MgO", "unit": "wt", "material": "xx"}
{"value": "1.8", "type": "Glass_Compound_Amount", "constituent": "Al2O3", "unit": "wt", "material": "xx"}
{"value": "0.8", "type": "Glass_Compound_Amount", "constituent": "K2O", "unit": "wt", "material": "xx"}