Appearances in the manga

 Gigalith and its line appeared a few times in several Pokemon manga.

Gigalith

-In Pokemon Special 517 : Something Suspicious, Cheren's Boldore evolved into a Gigalith after is battle with Hood Man at the Unova League. No trade was involved like it would normally in the games.

Cheren's Gigalith fighting Black's Emboar

- In Pokemon RéBurst, a Japan only manga where humans can turn into pokemon hybrids using a technique called Burst, the Rock type form of Fraud, an antagonist, is Gigalith.

A Human-Gigalith hybrid

Boldore

-In Pokemon Special 517 : Something Suspicious, Cheren's Boldore first appeared and evolved.

-In Pokemon Special 489, Drawing Bridges, and in Pokemon Special 547, The Last Battle a trainer's Boldore appeared.

-In the Sword and Shield chapter, a Boldore was seen in the Wild Area.

-In Challenge the Battle Subway !, a chapter of Be the Best ! Pokemon B+W (a one volume manga based on Pokemon Black and White by Kaoto Katsumi), the main character, Monta, uses a freshly evolved Boldore in the Battle Subway.

Monta's Boldore using Smack Down

-In Pokemon RéBurst, a character called Rend has a Boldore Burst form.

A Human-Boldore hybrid

-In Pokémon + Nobunaga's Ambition ~ Ranse's Color Picture Scroll ~, a six chapter manga adaptation of the game Pokemon Conquest, a Boldore appeared in the chapter The Green Scroll : Kenshin's Adventure. It was under the ownership of Ujiyasu, the Warlord of Cragspur (Rock type kingdom)

Boldore vs Gallade

Roggenrola

- In Pokemon Special 464 : Black's First Trainer Battle, a Hiker named Andy uses a Roggenrola during his Triple Battle with Black. It was defeated after Andy became dehydrated.

Andy's Roggenrola

-In the Be the Best ! Pokemon B+W chapter The Key to Triple Battles, Monta uses a Roggenrola against Cheren. It defeated Cheren's Pansage and Basculin.

Monta's Roggenrola using Rock Slide

-In Pocket Monsters BW : Good Partners, another manga based on Black and White, three Roggenrola appeared in the fourth chapter.

-In Pocket Monsters BW : The Heroes of Fire and Thunder, a similar manga, a Roggenrola appeared in the second chapter.

-In Pokémon + Nobunaga's Ambition ~ Ranse's Color Picture Scroll ~, a Roggenrola appeared in the same chapter as the Boldore.

Source ;

-Bulbapedia