| Clue | Source | Date |
|---|---|---|
| Some fire starters | ||
| Spark producers | Thomas Joseph | 19 Dec 2022 |
| Spark-producing rocks | USA Today | 02 Oct 2022 |
| Fire-starting rocks | Newsday | 16 Feb 2022 |
| Spares for lighters | The Telegraph Quick | 26 Feb 2021 |
| Fire-starting stones | Universal | 17 Dec 2017 |
| Spark producers | The Washington Post | 29 Apr 2017 |
| Spark producers | LA Times Daily | 29 Apr 2017 |
| Fire-starting stones | ||
| Spark producers | ||
| Spark producers | Universal | 07 Sep 2015 |
| Spark producers | ||
| Fire-starting stones | ||
| Spark-producing stones | ||
| Spark-producing stones | ||
| Stones for starting fires | ||
| Prehistoric tools | ||
| Fire-striking stones | ||
| Spark producers | ||
| Spark makers | ||
| Lighter needs | ||
| Spark makers | ||
| Lighters need these | ||
| Pieces of hard stone. | ||
| Lighter essentials. | ||
| Primitive implements. | ||
| Hard pieces of quartz. | ||
| Parts of cigarette lighters. | ||
| Fire stones. |