|                                      | Potassium | Potassium | Potassium | Rubidium | Rubidium | Rubidium |
|                                      | 8:1       | 6:1       | 4:1       | 8:1      | 6:1      | 4:1      |
| Density maximum                      | 8         | 10        | 12        | 20       | 25       | 20       |
| Predicted maximum from Raman spectra | 20        | 21        | 25        | 20       | 25       | 25       |

Caption: Maximum measured density of K and Rb 8:1, 6:1 and 4:1 glasses vs. maximum density predicted from Raman data

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": "8", "type": "Other"}
{"value": "1", "type": "Other"}
{"value": "6", "type": "Other"}
{"value": "1", "type": "Other"}
{"value": "4", "type": "Other"}
{"value": "1", "type": "Other"}
{"value": "8", "type": "Other"}
{"value": "1", "type": "Other"}
{"value": "6", "type": "Other"}
{"value": "1", "type": "Other"}
{"value": "4", "type": "Other"}
{"value": "1", "type": "Other"}
{"value": "8", "type": "Other"}
{"value": "10", "type": "Other"}
{"value": "12", "type": "Other"}
{"value": "20", "type": "Other"}
{"value": "25", "type": "Other"}
{"value": "20", "type": "Other"}
{"value": "20", "type": "Other"}
{"value": "21", "type": "Other"}
{"value": "25", "type": "Other"}
{"value": "20", "type": "Other"}
{"value": "25", "type": "Other"}
{"value": "25", "type": "Other"}