| # | Clue | Answer As Given | Value | Round | Category | Air Date | Show |
|---|---|---|---|---|---|---|---|
| The number used to designate a pencil's hardness, relates to the ratio of clay to this material, a form of carbon | graphite DD | $3,000 | DJ | HARD SCIENCE | 2021-04-26 | #8386 | |
| To make pencil lead, this form of carbon is mixed with clay | graphite | $400 | J | SCIENCE | 1991-11-20 | #1663 | |
| This form of carbon can be used as a lubricant or to write out an order to buy it | graphite | $1,000 | DJ | PHYSICAL SCIENCE | 1989-04-11 | #1072 |