Question: What material is the trophy the Current holders who play their home games at Bridgestone Area, made of?

Context paragraphs:
List of Nashville Predators general managers: The Nashville Predators are an American professional ice hockey team based in Nashville, Tennessee.  They play in the Central Division of the Western Conference in the National Hockey League (NHL).  The team joined the NHL in 1998 as an expansion team and have played their home games at the Bridgestone Arena since their inaugural season.  David Poile has been the team's general manager since their inception.

Clarence S. Campbell Bowl: The Clarence S. Campbell Bowl, or simply the Campbell Bowl, is a National Hockey League trophy awarded to the Western Conference playoff champions.  It is named after Clarence S. Campbell, who served as President of the NHL from to .  The trophy itself is constructed of sterling silver, crafted in 1878.  The Nashville Predators are the current holders of the trophy after winning the 2017 Western Conference Final.

Marching Jayhawks: The Marching Jayhawks, is a 270-piece marching band consisting of woodwinds, brass, percussion, and color guard, representing the University of Kansas in Lawrence, Kansas.  The band performs at all home football games and occasionally travels to away games.  They also send smaller ensembles to pep rallies around the Kansas City area.  The band marches in parades on campus and in downtown Lawrence.  The volleyball and basketball pep bands play at all home games and will often travel for post-season play.  The band was awarded the Sudler Trophy in 1989.

List of Nashville Kats seasons: This is a list of seasons completed by the Nashville Kats.  The Kats were a professional arena football franchise of the Arena Football League.  The team was established in 1997.  They made the playoffs in their first five years in existence.  However, after the 2001 season, the Kats players and equipment became the nucleus of the Georgia Force AFL franchise, although the Kats' history remained in Nashville.  After being dormant for three seasons, the Kats were resurrected in 2005.  However, the Kats folded after the 2007 season due to box office struggles as the revived Kats never approached the popularity of the previous team.  The Kats played in two ArenaBowls and they played their home games at Bridgestone Arena, formermly the Nashville Arena, Gaylord Entertainment Center, and Sommet Center.

2009 NHL Winter Classic: The 2009 NHL Winter Classic (known via corporate sponsorship as the Bridgestone NHL Winter Classic 2009) was an outdoor regular season National Hockey League (NHL) game played on January 1, 2009, at Wrigley Field in Chicago, Illinois.  The game pitted the Chicago Blackhawks, who normally play their home games indoors at United Center, against the defending Stanley Cup champion Detroit Red Wings in the 701st game between these rivals in the NHL's Central Division.  The Red Wings won the game, 6–4, despite falling behind 3–1 in the first period.  This was the first Winter Classic to involve at least one of the Original Six teams, and the first to feature teams from the Western Conference.

List of Nashville Predators head coaches: The Nashville Predators are an American professional ice hockey team based in Nashville, Tennessee.  They play in the Central Division of the Western Conference in the National Hockey League (NHL).  The team joined the NHL in 1998 as an expansion team.  The Predators have played their home games at the Bridgestone Arena since their inaugural season.  The Predators are owned by Predators Holdings LLC, David Poile is their general manager.

Duke of York Young Champions Trophy: First played in 2001, the Duke of York Young Champions Trophy is a unique, international 54-hole stroke play golf tournament for boys and girls who are either the current holders of their Under 18 National Championship or have won some other major golfing event in the preceding twelve months.  The event is supported by the R&A and their affiliated national governing bodies and counts towards the World Amateur Golf Rankings and the American Junior Golf Association's performance based entry system.

Killik Cup: The Killik Cup is a rugby union competitive trophy awarded to Barbarians and their international competitors.  Killik & Co are currently the sponsors for all Barbarians matches that takes place at the English rugby union home stadium Twickenham Stadium in London.  The cup was first contested in 2009 when the Barbarians played the All Blacks, where on that occasion, the Baa-Baas were the victors 25–18.  However the current holders is the International opposition in Australia, when the Wallabies won 40–36 at Twickenham during their 2014 November tests.  2015 Winners of the Killik Cup Were Argentina who won 31-49 on the 21st November.

Rochdale RUFC: Rochdale Rugby Football Club is an English rugby union team based in Rochdale, Greater Manchester.  The first XV currently plays in North 1 West, a sixth level league in the English league system.  The first XV are the current holders of the Lancashire Trophy and are the most successful club in this competition, winning the competition a total of 5 times.  Each weekend the club field 4 senior sides along with mini & junior teams from under 7's through to senior colts.  The 'Expendables' (over 35's) play invitational games during the season.

Nashville Predators: The Nashville Predators are a professional ice hockey team based in Nashville, Tennessee.  They are members of the Central Division of the Western Conference of the National Hockey League (NHL).  The Predators joined the NHL as an expansion team in the 1998–99 season, and play their home games at Bridgestone Arena.

Supporting paragraphs: Clarence S. Campbell Bowl Nashville Predators
Answer: sterling silver