def METHOD_NAME(group=""):
    """
    Extract a mineral group from the database.
    Parameters
    -----------
    group : :class:`str`
        Group to extract from the mineral database.
    Returns
    ---------
    :class:`pandas.DataFrame`
        Dataframe of group members and compositions.
    """
    assert group in list_groups()
    with TinyDB(str(__dbpath__), access_mode="r") as db:
        grp = db.search(Query().group == group)
    df = pd.DataFrame(grp)
    meta, chem = (
        ["name", "formula"],
        [i for i in df.columns if i not in ["name", "formula", "group"]],
    )
    df = df.reindex(columns=meta + chem)
    df.loc[:, chem] = df.loc[:, chem].apply(pd.to_numeric)
    df = df.loc[:, (df != 0).any(axis=0)]  # remove zero-only columns
    return df